fcc1_0d68

Unordered Tetrad Three Gene Mapping

In this problem, you will use unordered tetrads to determine the between a single pair of genes and calculate the distances between them. The yeast Saccharomyces cerevisiae is used in this study. A cross has been performed to study the linkage relationships among three genes, and the resulting genotypes are summarized in the table below.

Characteristics of Recessive Phenotypes

Gene A is analogous to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene E is analogous to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene T is associated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

241

14,462

5,874

7,716

226

401

TOTAL =

28,920

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and T

distance =

½(5,874) + 3×(226 + 241)

28,920

2,937 + 1,401

28,920

4,338

28,920

= 0.1500 = 15 cM Incorrect distance =

½(5,874) + 3×(226)

28,920

2,937 + 678

28,920

3,615

28,920

= 0.1250 = 12.50 cM Incorrect distance =

½(5,874 + 7,716) + 3×(226 + 401)

28,920

6,795 + 1,881

28,920

8,676

28,920

= 0.3000 = 30 cM Incorrect distance =

½(7,716) + 3×(401)

28,920

3,858 + 1,203

28,920

5,061

28,920

= 0.1750 = 17.50 cM Incorrect distance =

½(7,716) + 3×(241 + 401)

28,920

3,858 + 1,926

28,920

5,784

28,920

= 0.2000 = 20 cM Correct MC

b3d2_28d8

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene J is correlated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

166

2,244

3,565

1,902

115

108

TOTAL =

8,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and N

distance =

½(1,902 + 2,244) + 3×(108 + 115 + 166)

8,100

2,073 + 1,167

8,100

3,240

8,100

= 0.4000 = 40 cM Incorrect distance =

½(1,902) + 3×(115)

8,100

951 + 345

8,100

1,296

8,100

= 0.1600 = 16 cM Incorrect distance =

½(2,244) + 3×(108 + 166)

8,100

1,122 + 822

8,100

1,944

8,100

= 0.2400 = 24 cM Correct distance =

½(1,902 + 2,244) + 3×(115 + 166)

8,100

2,073 + 843

8,100

2,916

8,100

= 0.3600 = 36 cM Incorrect distance =

½(2,244) + 3×(166)

8,100

1,122 + 498

8,100

1,620

8,100

= 0.2000 = 20 cM Incorrect MC

5aeb_0d66

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

11,467

3,762

7,656

362

TOTAL =

23,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and P

distance =

½(3,762 + 7,656) + 3×(75 + 362)

23,400

5,709 + 1,311

23,400

7,020

23,400

= 0.3000 = 30 cM Correct distance =

½(7,656) + 3×(362)

23,400

3,828 + 1,086

23,400

4,914

23,400

= 0.2100 = 21 cM Incorrect distance =

½(3,762) + 3×(75 + 78)

23,400

1,881 + 459

23,400

2,340

23,400

= 0.1000 = 10 cM Incorrect distance =

½(3,762) + 3×(75)

23,400

1,881 + 225

23,400

2,106

23,400

= 0.0900 = 9 cM Incorrect distance =

½(3,762 + 7,656) + 3×(75 + 78 + 362)

23,400

5,709 + 1,545

23,400

7,254

23,400

= 0.3100 = 31 cM Incorrect MC

0b77_0f5b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is associated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

103

1,596

2,831

1,452

TOTAL =

6,150

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and M

distance =

½(1,452) + 3×(82 + 86)

6,150

726 + 504

6,150

1,230

6,150

= 0.2000 = 20 cM Correct distance =

½(1,452 + 1,596) + 3×(82 + 86 + 103)

6,150

1,524 + 813

6,150

2,337

6,150

= 0.3800 = 38 cM Incorrect distance =

½(1,452 + 1,596) + 3×(86 + 103)

6,150

1,524 + 567

6,150

2,091

6,150

= 0.3400 = 34 cM Incorrect distance =

½(1,596) + 3×(103)

6,150

798 + 309

6,150

1,107

6,150

= 0.1800 = 18 cM Incorrect distance =

½(1,452) + 3×(86)

6,150

726 + 258

6,150

984

6,150

= 0.1600 = 16 cM Incorrect MC

1066_03a2

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is associated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene M is associated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

335

4,920

474

5,670

231

8,170

TOTAL =

19,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and M

distance =

½(4,920 + 5,670) + 3×(335 + 474)

19,800

5,295 + 2,427

19,800

7,722

19,800

= 0.3900 = 39 cM Correct distance =

½(4,920) + 3×(231 + 335)

19,800

2,460 + 1,698

19,800

4,158

19,800

= 0.2100 = 21 cM Incorrect distance =

½(5,670) + 3×(231 + 474)

19,800

2,835 + 2,115

19,800

4,950

19,800

= 0.2500 = 25 cM Incorrect distance =

½(5,670) + 3×(474)

19,800

2,835 + 1,422

19,800

4,257

19,800

= 0.2150 = 21.50 cM Incorrect distance =

½(4,920 + 5,670) + 3×(231 + 335 + 474)

19,800

5,295 + 3,120

19,800

8,415

19,800

= 0.4250 = 42.50 cM Incorrect MC

19bd_7b82

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is related to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

3,924

129

310

7,686

13,674

TOTAL =

25,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and K

distance =

½(3,924) + 3×(77 + 129)

25,800

1,962 + 618

25,800

2,580

25,800

= 0.1000 = 10 cM Correct distance =

½(3,924 + 7,686) + 3×(129)

25,800

5,805 + 387

25,800

6,192

25,800

= 0.2400 = 24 cM Incorrect distance =

½(3,924 + 7,686) + 3×(77 + 310)

25,800

5,805 + 1,161

25,800

6,966

25,800

= 0.2700 = 27 cM Incorrect distance =

½(7,686) + 3×(310)

25,800

3,843 + 930

25,800

4,773

25,800

= 0.1850 = 18.50 cM Incorrect distance =

½(7,686) + 3×(129 + 310)

25,800

3,843 + 1,317

25,800

5,160

25,800

= 0.2000 = 20 cM Incorrect MC

291b_7888

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene F is correlated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.

Set #

Tetrad Genotypes

Progeny
Count

2,940

4,146

17,342

TOTAL =

24,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and F

distance =

½(4,146) + 3×(41 + 88)

24,600

2,073 + 387

24,600

2,460

24,600

= 0.1000 = 10 cM Incorrect distance =

½(2,940) + 3×(43)

24,600

1,470 + 129

24,600

1,599

24,600

= 0.0650 = 6.50 cM Incorrect distance =

½(4,146) + 3×(88)

24,600

2,073 + 264

24,600

2,337

24,600

= 0.0950 = 9.50 cM Incorrect distance =

½(2,940 + 4,146) + 3×(43 + 88)

24,600

3,543 + 393

24,600

3,936

24,600

= 0.1600 = 16 cM Incorrect distance =

½(2,940) + 3×(41 + 43)

24,600

1,470 + 252

24,600

1,722

24,600

= 0.0700 = 7 cM Correct MC

1d32_3316

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is analogous to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is related to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.

Set #

Tetrad Genotypes

Progeny
Count

162

6,642

3,990

4,758

253

395

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and H

distance =

½(4,758) + 3×(162 + 395)

16,200

2,379 + 1,671

16,200

4,050

16,200

= 0.2500 = 25 cM Correct distance =

½(4,758) + 3×(395)

16,200

2,379 + 1,185

16,200

3,564

16,200

= 0.2200 = 22 cM Incorrect distance =

½(3,990 + 4,758) + 3×(162 + 253 + 395)

16,200

4,374 + 2,430

16,200

6,804

16,200

= 0.4200 = 42 cM Incorrect distance =

½(3,990) + 3×(162 + 253)

16,200

1,995 + 1,245

16,200

3,240

16,200

= 0.2000 = 20 cM Incorrect distance =

½(3,990 + 4,758) + 3×(162)

16,200

4,374 + 486

16,200

4,860

16,200

= 0.3000 = 30 cM Incorrect MC

b70c_03a1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene N is related to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene X is connected with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is linked with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,596

134

4,554

7,753

TOTAL =

14,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes X and Y

distance =

½(4,554) + 3×(47 + 134)

14,100

2,277 + 543

14,100

2,820

14,100

= 0.2000 = 20 cM Correct distance =

½(1,596) + 3×(16)

14,100

798 + 48

14,100

846

14,100

= 0.0600 = 6 cM Incorrect distance =

½(1,596 + 4,554) + 3×(16 + 47 + 134)

14,100

3,075 + 591

14,100

3,666

14,100

= 0.2600 = 26 cM Incorrect distance =

½(1,596) + 3×(16 + 47)

14,100

798 + 189

14,100

987

14,100

= 0.0700 = 7 cM Incorrect distance =

½(1,596 + 4,554) + 3×(16 + 134)

14,100

3,075 + 450

14,100

3,525

14,100

= 0.2500 = 25 cM Incorrect MC

7138_e03c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is associated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene P is affiliated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

3,390

4,725

786

TOTAL =

9,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and P

distance =

½(786 + 3,390) + 3×(15)

9,000

2,088 + 45

9,000

2,133

9,000

= 0.2370 = 23.70 cM Incorrect distance =

½(786 + 3,390) + 3×(4 + 15 + 80)

9,000

2,088 + 297

9,000

2,385

9,000

= 0.2650 = 26.50 cM Incorrect distance =

½(786 + 3,390) + 3×(4 + 80)

9,000

2,088 + 252

9,000

2,340

9,000

= 0.2600 = 26 cM Correct distance =

½(786) + 3×(4 + 15)

9,000

393 + 57

9,000

450

9,000

= 0.0500 = 5 cM Incorrect distance =

½(3,390) + 3×(15 + 80)

9,000

1,695 + 285

9,000

1,980

9,000

= 0.2200 = 22 cM Incorrect MC

0eda_1970

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

972

888

1,725

TOTAL =

3,750

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and K

distance =

½(972) + 3×(63)

3,750

486 + 189

3,750

675

3,750

= 0.1800 = 18 cM Incorrect distance =

½(888) + 3×(50 + 52)

3,750

444 + 306

3,750

750

3,750

= 0.2000 = 20 cM Correct distance =

½(888 + 972) + 3×(50 + 52 + 63)

3,750

930 + 495

3,750

1,425

3,750

= 0.3800 = 38 cM Incorrect distance =

½(888 + 972) + 3×(52 + 63)

3,750

930 + 345

3,750

1,275

3,750

= 0.3400 = 34 cM Incorrect distance =

½(972) + 3×(50 + 63)

3,750

486 + 339

3,750

825

3,750

= 0.2200 = 22 cM Incorrect MC

4c7d_1430

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is associated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene H is related to the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

17,390

3,408

4,200

TOTAL =

25,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and M

distance =

½(4,200) + 3×(42 + 98)

25,200

2,100 + 420

25,200

2,520

25,200

= 0.1000 = 10 cM Incorrect distance =

½(3,408 + 4,200) + 3×(62 + 98)

25,200

3,804 + 480

25,200

4,284

25,200

= 0.1700 = 17 cM Incorrect distance =

½(3,408) + 3×(42 + 62)

25,200

1,704 + 312

25,200

2,016

25,200

= 0.0800 = 8 cM Correct distance =

½(4,200) + 3×(98)

25,200

2,100 + 294

25,200

2,394

25,200

= 0.0950 = 9.50 cM Incorrect distance =

½(3,408 + 4,200) + 3×(42 + 62 + 98)

25,200

3,804 + 606

25,200

4,410

25,200

= 0.1750 = 17.50 cM Incorrect MC

5f91_5d47

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene N is related to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene Y is connected with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

102

9,588

2,484

7,920

278

TOTAL =

20,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and Y

distance =

½(2,484 + 7,920) + 3×(28 + 278)

20,400

5,202 + 918

20,400

6,120

20,400

= 0.3000 = 30 cM Incorrect distance =

½(2,484 + 7,920) + 3×(102)

20,400

5,202 + 306

20,400

5,508

20,400

= 0.2700 = 27 cM Incorrect distance =

½(7,920) + 3×(102 + 278)

20,400

3,960 + 1,140

20,400

5,100

20,400

= 0.2500 = 25 cM Incorrect distance =

½(2,484) + 3×(28 + 102)

20,400

1,242 + 390

20,400

1,632

20,400

= 0.0800 = 8 cM Correct distance =

½(2,484) + 3×(28)

20,400

1,242 + 84

20,400

1,326

20,400

= 0.0650 = 6.50 cM Incorrect MC

3e46_265c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is related to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is related to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene W is affiliated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

195

3,870

240

375

5,310

8,010

TOTAL =

18,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and W

distance =

½(3,870) + 3×(195)

18,000

1,935 + 585

18,000

2,520

18,000

= 0.1400 = 14 cM Incorrect distance =

½(3,870 + 5,310) + 3×(195 + 375)

18,000

4,590 + 1,710

18,000

6,300

18,000

= 0.3500 = 35 cM Correct distance =

½(5,310) + 3×(240 + 375)

18,000

2,655 + 1,845

18,000

4,500

18,000

= 0.2500 = 25 cM Incorrect distance =

½(3,870 + 5,310) + 3×(195 + 240 + 375)

18,000

4,590 + 2,430

18,000

7,020

18,000

= 0.3900 = 39 cM Incorrect distance =

½(3,870) + 3×(375)

18,000

1,935 + 1,125

18,000

3,060

18,000

= 0.1700 = 17 cM Incorrect MC

b481_e255

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene R is linked with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene T is analogous to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene X is affiliated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

7,330

2,388

5,508

252

TOTAL =

15,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes R and T

distance =

½(5,508) + 3×(78 + 252)

15,600

2,754 + 990

15,600

3,744

15,600

= 0.2400 = 24 cM Incorrect distance =

½(2,388) + 3×(44 + 78)

15,600

1,194 + 366

15,600

1,560

15,600

= 0.1000 = 10 cM Incorrect distance =

½(5,508) + 3×(44 + 78)

15,600

2,754 + 366

15,600

3,120

15,600

= 0.2000 = 20 cM Incorrect distance =

½(2,388 + 5,508) + 3×(44 + 252)

15,600

3,948 + 888

15,600

4,836

15,600

= 0.3100 = 31 cM Correct distance =

½(2,388) + 3×(78 + 252)

15,600

1,194 + 990

15,600

2,184

15,600

= 0.1400 = 14 cM Incorrect MC

9282_ca27

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene F is correlated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,176

2,040

1,320

108

TOTAL =

4,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and Y

distance =

½(1,320) + 3×(72 + 108)

4,800

660 + 540

4,800

1,200

4,800

= 0.2500 = 25 cM Incorrect distance =

½(1,176 + 1,320) + 3×(84 + 108)

4,800

1,248 + 576

4,800

1,824

4,800

= 0.3800 = 38 cM Correct distance =

½(1,320) + 3×(72 + 84)

4,800

660 + 468

4,800

1,128

4,800

= 0.2350 = 23.50 cM Incorrect distance =

½(1,176) + 3×(72 + 84)

4,800

588 + 468

4,800

1,056

4,800

= 0.2200 = 22 cM Incorrect distance =

½(1,320) + 3×(84)

4,800

660 + 252

4,800

912

4,800

= 0.1900 = 19 cM Incorrect MC

0247_68c0

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene X is connected with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

279

6,474

13,677

8,076

497

TOTAL =

29,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and X

distance =

½(8,076) + 3×(497)

29,100

4,038 + 1,491

29,100

5,529

29,100

= 0.1900 = 19 cM Incorrect distance =

½(6,474) + 3×(279)

29,100

3,237 + 837

29,100

4,074

29,100

= 0.1400 = 14 cM Incorrect distance =

½(6,474) + 3×(97 + 279)

29,100

3,237 + 1,128

29,100

4,365

29,100

= 0.1500 = 15 cM Incorrect distance =

½(6,474 + 8,076) + 3×(97)

29,100

7,275 + 291

29,100

7,566

29,100

= 0.2600 = 26 cM Incorrect distance =

½(8,076) + 3×(97 + 497)

29,100

4,038 + 1,782

29,100

5,820

29,100

= 0.2000 = 20 cM Correct MC

ac02_c67c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene J is analogous to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene K is associated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

252

6,258

11,130

3,192

105

TOTAL =

21,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and K

distance =

½(6,258) + 3×(105)

21,000

3,129 + 315

21,000

3,444

21,000

= 0.1640 = 16.40 cM Incorrect distance =

½(6,258) + 3×(105 + 252)

21,000

3,129 + 1,071

21,000

4,200

21,000

= 0.2000 = 20 cM Correct distance =

½(3,192 + 6,258) + 3×(105)

21,000

4,725 + 315

21,000

5,040

21,000

= 0.2400 = 24 cM Incorrect distance =

½(3,192 + 6,258) + 3×(63 + 252)

21,000

4,725 + 945

21,000

5,670

21,000

= 0.2700 = 27 cM Incorrect distance =

½(3,192) + 3×(63 + 105)

21,000

1,596 + 504

21,000

2,100

21,000

= 0.1000 = 10 cM Incorrect MC

086e_c541

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene P is correlated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene T is associated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,518

4,048

2,340

123

TOTAL =

8,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and T

distance =

½(1,518 + 2,340) + 3×(44 + 123)

8,100

1,929 + 501

8,100

2,430

8,100

= 0.3000 = 30 cM Incorrect distance =

½(2,340) + 3×(27 + 123)

8,100

1,170 + 450

8,100

1,620

8,100

= 0.2000 = 20 cM Incorrect distance =

½(2,340) + 3×(123)

8,100

1,170 + 369

8,100

1,539

8,100

= 0.1900 = 19 cM Incorrect distance =

½(1,518) + 3×(27 + 44)

8,100

759 + 213

8,100

972

8,100

= 0.1200 = 12 cM Correct distance =

½(1,518) + 3×(44)

8,100

759 + 132

8,100

891

8,100

= 0.1100 = 11 cM Incorrect MC

bd4d_86a8

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is correlated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene C is associated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene R is related to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

1,608

6,204

5,124

180

TOTAL =

13,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and C

distance =

½(5,124) + 3×(66 + 180)

13,200

2,562 + 738

13,200

3,300

13,200

= 0.2500 = 25 cM Incorrect distance =

½(1,608 + 5,124) + 3×(18 + 180)

13,200

3,366 + 594

13,200

3,960

13,200

= 0.3000 = 30 cM Incorrect distance =

½(5,124) + 3×(180)

13,200

2,562 + 540

13,200

3,102

13,200

= 0.2350 = 23.50 cM Incorrect distance =

½(1,608) + 3×(18 + 66)

13,200

804 + 252

13,200

1,056

13,200

= 0.0800 = 8 cM Correct distance =

½(1,608 + 5,124) + 3×(66)

13,200

3,366 + 198

13,200

3,564

13,200

= 0.2700 = 27 cM Incorrect MC

ab9b_1cd7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is linked with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene T is affiliated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

265

3,306

109

2,406

4,080

TOTAL =

10,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and T

distance =

½(3,306) + 3×(265)

10,200

1,653 + 795

10,200

2,448

10,200

= 0.2400 = 24 cM Incorrect distance =

½(2,406) + 3×(109)

10,200

1,203 + 327

10,200

1,530

10,200

= 0.1500 = 15 cM Incorrect distance =

½(2,406 + 3,306) + 3×(34)

10,200

2,856 + 102

10,200

2,958

10,200

= 0.2900 = 29 cM Incorrect distance =

½(2,406 + 3,306) + 3×(34 + 109 + 265)

10,200

2,856 + 1,224

10,200

4,080

10,200

= 0.4000 = 40 cM Incorrect distance =

½(2,406) + 3×(34 + 109)

10,200

1,203 + 429

10,200

1,632

10,200

= 0.1600 = 16 cM Correct MC

1baf_19b9

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is affiliated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene X is related to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

3,570

413

10,626

12,558

TOTAL =

27,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and X

distance =

½(3,570 + 10,626) + 3×(42 + 413)

27,300

7,098 + 1,365

27,300

8,463

27,300

= 0.3100 = 31 cM Incorrect distance =

½(3,570 + 10,626) + 3×(91)

27,300

7,098 + 273

27,300

7,371

27,300

= 0.2700 = 27 cM Incorrect distance =

½(3,570) + 3×(42 + 91)

27,300

1,785 + 399

27,300

2,184

27,300

= 0.0800 = 8 cM Incorrect distance =

½(10,626) + 3×(91 + 413)

27,300

5,313 + 1,512

27,300

6,825

27,300

= 0.2500 = 25 cM Correct distance =

½(3,570 + 10,626) + 3×(42 + 91 + 413)

27,300

7,098 + 1,638

27,300

8,736

27,300

= 0.3200 = 32 cM Incorrect MC

a4d9_a407

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is related to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene X is associated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

2,430

132

6,006

4,302

251

TOTAL =

13,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and X

distance =

½(4,302) + 3×(251)

13,200

2,151 + 753

13,200

2,904

13,200

= 0.2200 = 22 cM Incorrect distance =

½(2,430) + 3×(79 + 132)

13,200

1,215 + 633

13,200

1,848

13,200

= 0.1400 = 14 cM Incorrect distance =

½(2,430) + 3×(79)

13,200

1,215 + 237

13,200

1,452

13,200

= 0.1100 = 11 cM Incorrect distance =

½(2,430 + 4,302) + 3×(79 + 251)

13,200

3,366 + 990

13,200

4,356

13,200

= 0.3300 = 33 cM Correct distance =

½(4,302) + 3×(132 + 251)

13,200

2,151 + 1,149

13,200

3,300

13,200

= 0.2500 = 25 cM Incorrect MC

7262_7dbe

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

1,050

112

5,538

6,750

TOTAL =

13,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and K

distance =

½(5,538) + 3×(45 + 112)

13,500

2,769 + 471

13,500

3,240

13,500

= 0.2400 = 24 cM Incorrect distance =

½(1,050) + 3×(5 + 45)

13,500

525 + 150

13,500

675

13,500

= 0.0500 = 5 cM Incorrect distance =

½(1,050) + 3×(5)

13,500

525 + 15

13,500

540

13,500

= 0.0400 = 4 cM Incorrect distance =

½(1,050 + 5,538) + 3×(5 + 112)

13,500

3,294 + 351

13,500

3,645

13,500

= 0.2700 = 27 cM Correct distance =

½(5,538) + 3×(112)

13,500

2,769 + 336

13,500

3,105

13,500

= 0.2300 = 23 cM Incorrect MC

6a61_235e

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is linked with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene N is analogous to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

103

2,484

3,055

912

TOTAL =

6,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and N

distance =

½(2,484) + 3×(103)

6,600

1,242 + 309

6,600

1,551

6,600

= 0.2350 = 23.50 cM Incorrect distance =

½(912 + 2,484) + 3×(13 + 103)

6,600

1,698 + 348

6,600

2,046

6,600

= 0.3100 = 31 cM Correct distance =

½(912 + 2,484) + 3×(13 + 33 + 103)

6,600

1,698 + 447

6,600

2,145

6,600

= 0.3250 = 32.50 cM Incorrect distance =

½(912) + 3×(13 + 33)

6,600

456 + 138

6,600

594

6,600

= 0.0900 = 9 cM Incorrect distance =

½(2,484) + 3×(33 + 103)

6,600

1,242 + 408

6,600

1,650

6,600

= 0.2500 = 25 cM Incorrect MC

caf5_0ae7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is associated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

2,022

6,205

4,656

214

TOTAL =

13,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and K

distance =

½(4,656) + 3×(66 + 214)

13,200

2,328 + 840

13,200

3,168

13,200

= 0.2400 = 24 cM Incorrect distance =

½(4,656) + 3×(214)

13,200

2,328 + 642

13,200

2,970

13,200

= 0.2250 = 22.50 cM Incorrect distance =

½(2,022) + 3×(37)

13,200

1,011 + 111

13,200

1,122

13,200

= 0.0850 = 8.50 cM Incorrect distance =

½(2,022 + 4,656) + 3×(37 + 214)

13,200

3,339 + 753

13,200

4,092

13,200

= 0.3100 = 31 cM Incorrect distance =

½(2,022) + 3×(37 + 66)

13,200

1,011 + 309

13,200

1,320

13,200

= 0.1000 = 10 cM Correct MC

e836_ffae

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is associated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene T is related to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene X is correlated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

8,822

1,086

2,616

TOTAL =

12,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and T

distance =

½(1,086) + 3×(8 + 21)

12,600

543 + 87

12,600

630

12,600

= 0.0500 = 5 cM Incorrect distance =

½(2,616) + 3×(21 + 47)

12,600

1,308 + 204

12,600

1,512

12,600

= 0.1200 = 12 cM Incorrect distance =

½(1,086 + 2,616) + 3×(8 + 47)

12,600

1,851 + 165

12,600

2,016

12,600

= 0.1600 = 16 cM Correct distance =

½(1,086 + 2,616) + 3×(8 + 21 + 47)

12,600

1,851 + 228

12,600

2,079

12,600

= 0.1650 = 16.50 cM Incorrect distance =

½(1,086) + 3×(8)

12,600

543 + 24

12,600

567

12,600

= 0.0450 = 4.50 cM Incorrect MC

20e0_49c4

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is related to the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene M is analogous to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene Y is connected with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

2,862

1,290

10,765

TOTAL =

15,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and Y

distance =

½(1,290 + 2,862) + 3×(10 + 48)

15,000

2,076 + 174

15,000

2,250

15,000

= 0.1500 = 15 cM Incorrect distance =

½(2,862) + 3×(10 + 25 + 48)

15,000

1,431 + 249

15,000

1,680

15,000

= 0.1120 = 11.20 cM Incorrect distance =

½(1,290) + 3×(10 + 25)

15,000

645 + 105

15,000

750

15,000

= 0.0500 = 5 cM Correct distance =

½(2,862) + 3×(48)

15,000

1,431 + 144

15,000

1,575

15,000

= 0.1050 = 10.50 cM Incorrect distance =

½(2,862) + 3×(25 + 48)

15,000

1,431 + 219

15,000

1,650

15,000

= 0.1100 = 11 cM Incorrect MC

449c_10ac

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is related to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene W is correlated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

3,030

7,522

780

TOTAL =

11,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and K

distance =

½(3,030) + 3×(19 + 46)

11,400

1,515 + 195

11,400

1,710

11,400

= 0.1500 = 15 cM Incorrect distance =

½(3,030) + 3×(46)

11,400

1,515 + 138

11,400

1,653

11,400

= 0.1450 = 14.50 cM Incorrect distance =

½(780) + 3×(3)

11,400

390 + 9

11,400

399

11,400

= 0.0350 = 3.50 cM Incorrect distance =

½(780 + 3,030) + 3×(3 + 46)

11,400

1,905 + 147

11,400

2,052

11,400

= 0.1800 = 18 cM Incorrect distance =

½(780) + 3×(3 + 19)

11,400

390 + 66

11,400

456

11,400

= 0.0400 = 4 cM Correct MC

cc76_f4d6

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is linked with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene X is analogous to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

2,670

7,917

6,378

300

TOTAL =

17,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and X

distance =

½(6,378) + 3×(87 + 300)

17,400

3,189 + 1,161

17,400

4,350

17,400

= 0.2500 = 25 cM Incorrect distance =

½(2,670) + 3×(48)

17,400

1,335 + 144

17,400

1,479

17,400

= 0.0850 = 8.50 cM Incorrect distance =

½(2,670) + 3×(48 + 87)

17,400

1,335 + 405

17,400

1,740

17,400

= 0.1000 = 10 cM Incorrect distance =

½(2,670 + 6,378) + 3×(48 + 87 + 300)

17,400

4,524 + 1,305

17,400

5,829

17,400

= 0.3350 = 33.50 cM Incorrect distance =

½(2,670 + 6,378) + 3×(48 + 300)

17,400

4,524 + 1,044

17,400

5,568

17,400

= 0.3200 = 32 cM Correct MC

09cc_af81

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is correlated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

517

6,186

365

5,370

8,910

252

TOTAL =

21,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and K

distance =

½(5,370) + 3×(365)

21,600

2,685 + 1,095

21,600

3,780

21,600

= 0.1750 = 17.50 cM Incorrect distance =

½(6,186) + 3×(517)

21,600

3,093 + 1,551

21,600

4,644

21,600

= 0.2150 = 21.50 cM Incorrect distance =

½(6,186) + 3×(252 + 517)

21,600

3,093 + 2,307

21,600

5,400

21,600

= 0.2500 = 25 cM Incorrect distance =

½(5,370 + 6,186) + 3×(365 + 517)

21,600

5,778 + 2,646

21,600

8,424

21,600

= 0.3900 = 39 cM Incorrect distance =

½(5,370) + 3×(252 + 365)

21,600

2,685 + 1,851

21,600

4,536

21,600

= 0.2100 = 21 cM Correct MC

2c0e_eb9f

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene H is associated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

316

4,836

306

449

5,670

8,823

TOTAL =

20,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and H

distance =

½(4,836 + 5,670) + 3×(316 + 449)

20,400

5,253 + 2,295

20,400

7,548

20,400

= 0.3700 = 37 cM Incorrect distance =

½(4,836) + 3×(306 + 316)

20,400

2,418 + 1,866

20,400

4,284

20,400

= 0.2100 = 21 cM Correct distance =

½(4,836 + 5,670) + 3×(306 + 316 + 449)

20,400

5,253 + 3,213

20,400

8,466

20,400

= 0.4150 = 41.50 cM Incorrect distance =

½(4,836) + 3×(316)

20,400

2,418 + 948

20,400

3,366

20,400

= 0.1650 = 16.50 cM Incorrect distance =

½(5,670) + 3×(306 + 449)

20,400

2,835 + 2,265

20,400

5,100

20,400

= 0.2500 = 25 cM Incorrect MC

ccd5_d107

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene N is correlated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

2,880

1,380

1,524

TOTAL =

6,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and W

distance =

½(1,380) + 3×(60 + 70)

6,000

690 + 390

6,000

1,080

6,000

= 0.1800 = 18 cM Correct distance =

½(1,380 + 1,524) + 3×(70 + 86)

6,000

1,452 + 468

6,000

1,920

6,000

= 0.3200 = 32 cM Incorrect distance =

½(1,524) + 3×(86)

6,000

762 + 258

6,000

1,020

6,000

= 0.1700 = 17 cM Incorrect distance =

½(1,380) + 3×(70)

6,000

690 + 210

6,000

900

6,000

= 0.1500 = 15 cM Incorrect distance =

½(1,380 + 1,524) + 3×(60 + 70 + 86)

6,000

1,452 + 648

6,000

2,100

6,000

= 0.3500 = 35 cM Incorrect MC

0882_8996

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is associated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene P is correlated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

123

11,808

5,316

6,738

221

394

TOTAL =

24,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and P

distance =

½(5,316 + 6,738) + 3×(123)

24,600

6,027 + 369

24,600

6,396

24,600

= 0.2600 = 26 cM Incorrect distance =

½(6,738) + 3×(123 + 394)

24,600

3,369 + 1,551

24,600

4,920

24,600

= 0.2000 = 20 cM Incorrect distance =

½(5,316 + 6,738) + 3×(123 + 221 + 394)

24,600

6,027 + 2,214

24,600

8,241

24,600

= 0.3350 = 33.50 cM Incorrect distance =

½(5,316) + 3×(123 + 221)

24,600

2,658 + 1,032

24,600

3,690

24,600

= 0.1500 = 15 cM Correct distance =

½(5,316 + 6,738) + 3×(221 + 394)

24,600

6,027 + 1,845

24,600

7,872

24,600

= 0.3200 = 32 cM Incorrect MC

466f_79f2

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is related to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene P is correlated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

1,194

108

3,798

6,271

TOTAL =

11,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and P

distance =

½(1,194) + 3×(10 + 19)

11,400

597 + 87

11,400

684

11,400

= 0.0600 = 6 cM Incorrect distance =

½(3,798) + 3×(19 + 108)

11,400

1,899 + 381

11,400

2,280

11,400

= 0.2000 = 20 cM Incorrect distance =

½(1,194 + 3,798) + 3×(10 + 108)

11,400

2,496 + 354

11,400

2,850

11,400

= 0.2500 = 25 cM Correct distance =

½(1,194) + 3×(10)

11,400

597 + 30

11,400

627

11,400

= 0.0550 = 5.50 cM Incorrect distance =

½(1,194 + 3,798) + 3×(10 + 19 + 108)

11,400

2,496 + 411

11,400

2,907

11,400

= 0.2550 = 25.50 cM Incorrect MC

6875_e115

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is associated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene E is analogous to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.

Set #

Tetrad Genotypes

Progeny
Count

291

5,844

7,590

2,670

TOTAL =

16,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and F

distance =

½(5,844) + 3×(291)

16,500

2,922 + 873

16,500

3,795

16,500

= 0.2300 = 23 cM Incorrect distance =

½(2,670 + 5,844) + 3×(50 + 291)

16,500

4,257 + 1,023

16,500

5,280

16,500

= 0.3200 = 32 cM Correct distance =

½(2,670) + 3×(50 + 55)

16,500

1,335 + 315

16,500

1,650

16,500

= 0.1000 = 10 cM Incorrect distance =

½(2,670) + 3×(50)

16,500

1,335 + 150

16,500

1,485

16,500

= 0.0900 = 9 cM Incorrect distance =

½(2,670 + 5,844) + 3×(50 + 55 + 291)

16,500

4,257 + 1,188

16,500

5,445

16,500

= 0.3300 = 33 cM Incorrect MC

1c87_88e1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene X is related to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

4,344

13,230

8,832

418

TOTAL =

27,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and W

distance =

½(4,344 + 8,832) + 3×(86 + 90 + 418)

27,000

6,588 + 1,782

27,000

8,370

27,000

= 0.3100 = 31 cM Incorrect distance =

½(4,344) + 3×(86 + 90)

27,000

2,172 + 528

27,000

2,700

27,000

= 0.1000 = 10 cM Correct distance =

½(8,832) + 3×(418)

27,000

4,416 + 1,254

27,000

5,670

27,000

= 0.2100 = 21 cM Incorrect distance =

½(4,344 + 8,832) + 3×(86 + 418)

27,000

6,588 + 1,512

27,000

8,100

27,000

= 0.3000 = 30 cM Incorrect distance =

½(8,832) + 3×(90 + 418)

27,000

4,416 + 1,524

27,000

5,940

27,000

= 0.2200 = 22 cM Incorrect MC

df2c_b0ef

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene W is linked with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene X is correlated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

4,669

1,626

3,624

178

TOTAL =

10,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes X and Y

distance =

½(1,626) + 3×(35)

10,200

813 + 105

10,200

918

10,200

= 0.0900 = 9 cM Incorrect distance =

½(3,624) + 3×(68 + 178)

10,200

1,812 + 738

10,200

2,550

10,200

= 0.2500 = 25 cM Correct distance =

½(3,624) + 3×(178)

10,200

1,812 + 534

10,200

2,346

10,200

= 0.2300 = 23 cM Incorrect distance =

½(1,626 + 3,624) + 3×(35 + 68 + 178)

10,200

2,625 + 843

10,200

3,468

10,200

= 0.3400 = 34 cM Incorrect distance =

½(1,626) + 3×(35 + 68)

10,200

813 + 309

10,200

1,122

10,200

= 0.1100 = 11 cM Incorrect MC

b5a7_6e0a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is connected with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

2,016

6,085

3,318

149

TOTAL =

11,700

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and N

distance =

½(3,318) + 3×(78 + 149)

11,700

1,659 + 681

11,700

2,340

11,700

= 0.2000 = 20 cM Incorrect distance =

½(3,318) + 3×(149)

11,700

1,659 + 447

11,700

2,106

11,700

= 0.1800 = 18 cM Incorrect distance =

½(2,016 + 3,318) + 3×(54 + 149)

11,700

2,667 + 609

11,700

3,276

11,700

= 0.2800 = 28 cM Incorrect distance =

½(2,016) + 3×(54 + 78)

11,700

1,008 + 396

11,700

1,404

11,700

= 0.1200 = 12 cM Correct distance =

½(2,016) + 3×(54)

11,700

1,008 + 162

11,700

1,170

11,700

= 0.1000 = 10 cM Incorrect MC

d410_1614

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene X is linked with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is correlated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,326

966

2,005

TOTAL =

4,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and X

distance =

½(966 + 1,326) + 3×(49 + 60 + 94)

4,500

1,146 + 609

4,500

1,755

4,500

= 0.3900 = 39 cM Incorrect distance =

½(966) + 3×(49)

4,500

483 + 147

4,500

630

4,500

= 0.1400 = 14 cM Incorrect distance =

½(1,326) + 3×(94)

4,500

663 + 282

4,500

945

4,500

= 0.2100 = 21 cM Incorrect distance =

½(966 + 1,326) + 3×(49 + 94)

4,500

1,146 + 429

4,500

1,575

4,500

= 0.3500 = 35 cM Correct distance =

½(1,326) + 3×(49 + 60)

4,500

663 + 327

4,500

990

4,500

= 0.2200 = 22 cM Incorrect MC

5d2d_0ec6

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene F is analogous to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene M is associated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

6,912

990

6,354

117

TOTAL =

14,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and F

distance =

½(990 + 6,354) + 3×(24)

14,400

3,672 + 72

14,400

3,744

14,400

= 0.2600 = 26 cM Incorrect distance =

½(990 + 6,354) + 3×(3 + 117)

14,400

3,672 + 360

14,400

4,032

14,400

= 0.2800 = 28 cM Correct distance =

½(990) + 3×(3 + 24)

14,400

495 + 81

14,400

576

14,400

= 0.0400 = 4 cM Incorrect distance =

½(990 + 6,354) + 3×(3 + 24 + 117)

14,400

3,672 + 432

14,400

4,104

14,400

= 0.2850 = 28.50 cM Incorrect distance =

½(6,354) + 3×(24 + 117)

14,400

3,177 + 423

14,400

3,600

14,400

= 0.2500 = 25 cM Incorrect MC

d312_722b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene F is linked with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

351

6,636

8,326

3,126

TOTAL =

18,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and P

distance =

½(3,126 + 6,636) + 3×(68 + 93 + 351)

18,600

4,881 + 1,536

18,600

6,417

18,600

= 0.3450 = 34.50 cM Incorrect distance =

½(3,126) + 3×(68 + 93)

18,600

1,563 + 483

18,600

2,046

18,600

= 0.1100 = 11 cM Incorrect distance =

½(6,636) + 3×(93 + 351)

18,600

3,318 + 1,332

18,600

4,650

18,600

= 0.2500 = 25 cM Incorrect distance =

½(3,126 + 6,636) + 3×(68 + 351)

18,600

4,881 + 1,257

18,600

6,138

18,600

= 0.3300 = 33 cM Correct distance =

½(3,126) + 3×(68)

18,600

1,563 + 204

18,600

1,767

18,600

= 0.0950 = 9.50 cM Incorrect MC

f005_6b21

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene J is connected with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene P is affiliated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

232

4,440

114

3,204

8,102

108

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and J

distance =

½(4,440) + 3×(108 + 232)

16,200

2,220 + 1,020

16,200

3,240

16,200

= 0.2000 = 20 cM Incorrect distance =

½(3,204 + 4,440) + 3×(114 + 232)

16,200

3,822 + 1,038

16,200

4,860

16,200

= 0.3000 = 30 cM Correct distance =

½(3,204 + 4,440) + 3×(108 + 114 + 232)

16,200

3,822 + 1,362

16,200

5,184

16,200

= 0.3200 = 32 cM Incorrect distance =

½(4,440) + 3×(232)

16,200

2,220 + 696

16,200

2,916

16,200

= 0.1800 = 18 cM Incorrect distance =

½(3,204) + 3×(108 + 114)

16,200

1,602 + 666

16,200

2,268

16,200

= 0.1400 = 14 cM Incorrect MC

dab5_56bd

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is analogous to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene D is linked with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene R is analogous to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

210

3,948

140

406

5,124

6,972

TOTAL =

16,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and R

distance =

½(5,124) + 3×(140 + 406)

16,800

2,562 + 1,638

16,800

4,200

16,800

= 0.2500 = 25 cM Incorrect distance =

½(3,948) + 3×(210)

16,800

1,974 + 630

16,800

2,604

16,800

= 0.1550 = 15.50 cM Incorrect distance =

½(3,948 + 5,124) + 3×(210 + 406)

16,800

4,536 + 1,848

16,800

6,384

16,800

= 0.3800 = 38 cM Correct distance =

½(3,948) + 3×(140 + 210)

16,800

1,974 + 1,050

16,800

3,024

16,800

= 0.1800 = 18 cM Incorrect distance =

½(5,124) + 3×(210)

16,800

2,562 + 630

16,800

3,192

16,800

= 0.1900 = 19 cM Incorrect MC

8a13_aae8

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is linked with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene Y is correlated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,968

15,164

5,508

108

TOTAL =

22,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and Y

distance =

½(1,968 + 5,508) + 3×(14 + 38 + 108)

22,800

3,738 + 480

22,800

4,218

22,800

= 0.1850 = 18.50 cM Incorrect distance =

½(5,508) + 3×(38 + 108)

22,800

2,754 + 438

22,800

3,192

22,800

= 0.1400 = 14 cM Incorrect distance =

½(1,968) + 3×(14)

22,800

984 + 42

22,800

1,026

22,800

= 0.0450 = 4.50 cM Incorrect distance =

½(1,968) + 3×(14 + 38)

22,800

984 + 156

22,800

1,140

22,800

= 0.0500 = 5 cM Incorrect distance =

½(1,968 + 5,508) + 3×(14 + 108)

22,800

3,738 + 366

22,800

4,104

22,800

= 0.1800 = 18 cM Correct MC

598d_6ccc

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is correlated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

272

5,928

7,895

2,574

TOTAL =

16,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and H

distance =

½(2,574 + 5,928) + 3×(47 + 84 + 272)

16,800

4,251 + 1,209

16,800

5,460

16,800

= 0.3250 = 32.50 cM Incorrect distance =

½(5,928) + 3×(84 + 272)

16,800

2,964 + 1,068

16,800

4,032

16,800

= 0.2400 = 24 cM Incorrect distance =

½(2,574) + 3×(47 + 84)

16,800

1,287 + 393

16,800

1,680

16,800

= 0.1000 = 10 cM Correct distance =

½(2,574 + 5,928) + 3×(47 + 272)

16,800

4,251 + 957

16,800

5,208

16,800

= 0.3100 = 31 cM Incorrect distance =

½(5,928) + 3×(272)

16,800

2,964 + 816

16,800

3,780

16,800

= 0.2250 = 22.50 cM Incorrect MC

9783_e8f6

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene T is related to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

405

11,094

12,627

3,396

TOTAL =

27,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and Y

distance =

½(3,396 + 11,094) + 3×(32 + 405)

27,600

7,245 + 1,311

27,600

8,556

27,600

= 0.3100 = 31 cM Correct distance =

½(11,094) + 3×(405)

27,600

5,547 + 1,215

27,600

6,762

27,600

= 0.2450 = 24.50 cM Incorrect distance =

½(11,094) + 3×(46 + 405)

27,600

5,547 + 1,353

27,600

6,900

27,600

= 0.2500 = 25 cM Incorrect distance =

½(3,396) + 3×(32 + 46)

27,600

1,698 + 234

27,600

1,932

27,600

= 0.0700 = 7 cM Incorrect distance =

½(3,396) + 3×(32)

27,600

1,698 + 96

27,600

1,794

27,600

= 0.0650 = 6.50 cM Incorrect MC

332b_df8d

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is analogous to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene X is connected with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

3,120

1,842

2,526

203

TOTAL =

7,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and F

distance =

½(1,842) + 3×(83)

7,800

921 + 249

7,800

1,170

7,800

= 0.1500 = 15 cM Incorrect distance =

½(1,842 + 2,526) + 3×(83 + 203)

7,800

2,184 + 858

7,800

3,042

7,800

= 0.3900 = 39 cM Correct distance =

½(1,842 + 2,526) + 3×(26)

7,800

2,184 + 78

7,800

2,262

7,800

= 0.2900 = 29 cM Incorrect distance =

½(1,842 + 2,526) + 3×(26 + 83 + 203)

7,800

2,184 + 936

7,800

3,120

7,800

= 0.4000 = 40 cM Incorrect distance =

½(1,842) + 3×(26 + 83)

7,800

921 + 327

7,800

1,248

7,800

= 0.1600 = 16 cM Incorrect MC

9b10_c2b1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is affiliated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene W is correlated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

858

8,318

3,348

TOTAL =

12,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and P

distance =

½(858 + 3,348) + 3×(4 + 51)

12,600

2,103 + 165

12,600

2,268

12,600

= 0.1800 = 18 cM Incorrect distance =

½(858) + 3×(4 + 21)

12,600

429 + 75

12,600

504

12,600

= 0.0400 = 4 cM Correct distance =

½(858) + 3×(4)

12,600

429 + 12

12,600

441

12,600

= 0.0350 = 3.50 cM Incorrect distance =

½(3,348) + 3×(21 + 51)

12,600

1,674 + 216

12,600

1,890

12,600

= 0.1500 = 15 cM Incorrect distance =

½(858 + 3,348) + 3×(4 + 21 + 51)

12,600

2,103 + 228

12,600

2,331

12,600

= 0.1850 = 18.50 cM Incorrect MC

efef_6bac

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene H is affiliated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene R is linked with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

2,382

133

3,378

8,424

TOTAL =

14,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and R

distance =

½(2,382) + 3×(59)

14,400

1,191 + 177

14,400

1,368

14,400

= 0.0950 = 9.50 cM Incorrect distance =

½(2,382 + 3,378) + 3×(24)

14,400

2,880 + 72

14,400

2,952

14,400

= 0.2050 = 20.50 cM Incorrect distance =

½(2,382) + 3×(24 + 59)

14,400

1,191 + 249

14,400

1,440

14,400

= 0.1000 = 10 cM Incorrect distance =

½(3,378) + 3×(24 + 133)

14,400

1,689 + 471

14,400

2,160

14,400

= 0.1500 = 15 cM Incorrect distance =

½(2,382 + 3,378) + 3×(59 + 133)

14,400

2,880 + 576

14,400

3,456

14,400

= 0.2400 = 24 cM Correct MC

d833_db19

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene D is connected with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

1,416

3,045

2,238

149

TOTAL =

6,960

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and M

distance =

½(1,416 + 2,238) + 3×(54 + 149)

6,960

1,827 + 609

6,960

2,436

6,960

= 0.3500 = 35 cM Incorrect distance =

½(1,416) + 3×(54 + 58)

6,960

708 + 336

6,960

1,044

6,960

= 0.1500 = 15 cM Incorrect distance =

½(1,416) + 3×(54)

6,960

708 + 162

6,960

870

6,960

= 0.1250 = 12.50 cM Incorrect distance =

½(2,238) + 3×(58 + 149)

6,960

1,119 + 621

6,960

1,740

6,960

= 0.2500 = 25 cM Correct distance =

½(1,416 + 2,238) + 3×(54 + 58 + 149)

6,960

1,827 + 783

6,960

2,610

6,960

= 0.3750 = 37.50 cM Incorrect MC

2046_52de

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is linked with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene J is analogous to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene R is connected with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

1,236

1,680

780

TOTAL =

3,840

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and R

distance =

½(1,236) + 3×(82)

3,840

618 + 246

3,840

864

3,840

= 0.2250 = 22.50 cM Incorrect distance =

½(1,236) + 3×(32 + 82)

3,840

618 + 342

3,840

960

3,840

= 0.2500 = 25 cM Correct distance =

½(780) + 3×(30 + 32)

3,840

390 + 186

3,840

576

3,840

= 0.1500 = 15 cM Incorrect distance =

½(780 + 1,236) + 3×(30 + 82)

3,840

1,008 + 336

3,840

1,344

3,840

= 0.3500 = 35 cM Incorrect distance =

½(780) + 3×(30)

3,840

390 + 90

3,840

480

3,840

= 0.1250 = 12.50 cM Incorrect MC

9d6b_8eca

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is affiliated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

369

5,130

6,352

3,282

116

TOTAL =

15,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and P

distance =

½(3,282) + 3×(51 + 116)

15,300

1,641 + 501

15,300

2,142

15,300

= 0.1400 = 14 cM Incorrect distance =

½(3,282) + 3×(116)

15,300

1,641 + 348

15,300

1,989

15,300

= 0.1300 = 13 cM Incorrect distance =

½(5,130) + 3×(51 + 369)

15,300

2,565 + 1,260

15,300

3,825

15,300

= 0.2500 = 25 cM Correct distance =

½(5,130) + 3×(369)

15,300

2,565 + 1,107

15,300

3,672

15,300

= 0.2400 = 24 cM Incorrect distance =

½(3,282 + 5,130) + 3×(51 + 116 + 369)

15,300

4,206 + 1,608

15,300

5,814

15,300

= 0.3800 = 38 cM Incorrect MC

73fd_02c9

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene R is connected with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

207

8,820

12,283

2,040

TOTAL =

23,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and R

distance =

½(8,820) + 3×(207)

23,400

4,410 + 621

23,400

5,031

23,400

= 0.2150 = 21.50 cM Incorrect distance =

½(2,040) + 3×(11 + 39)

23,400

1,020 + 150

23,400

1,170

23,400

= 0.0500 = 5 cM Incorrect distance =

½(8,820) + 3×(39 + 207)

23,400

4,410 + 738

23,400

5,148

23,400

= 0.2200 = 22 cM Correct distance =

½(2,040 + 8,820) + 3×(11 + 39 + 207)

23,400

5,430 + 771

23,400

6,201

23,400

= 0.2650 = 26.50 cM Incorrect distance =

½(2,040 + 8,820) + 3×(11 + 207)

23,400

5,430 + 654

23,400

6,084

23,400

= 0.2600 = 26 cM Incorrect MC

d7e1_ffb3

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is related to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

4,110

14,188

7,038

289

TOTAL =

25,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes W and Y

distance =

½(4,110 + 7,038) + 3×(89 + 289)

25,800

5,574 + 1,134

25,800

6,708

25,800

= 0.2600 = 26 cM Correct distance =

½(4,110) + 3×(89)

25,800

2,055 + 267

25,800

2,322

25,800

= 0.0900 = 9 cM Incorrect distance =

½(7,038) + 3×(86 + 289)

25,800

3,519 + 1,125

25,800

4,644

25,800

= 0.1800 = 18 cM Incorrect distance =

½(4,110 + 7,038) + 3×(86 + 89 + 289)

25,800

5,574 + 1,392

25,800

6,966

25,800

= 0.2700 = 27 cM Incorrect distance =

½(7,038) + 3×(289)

25,800

3,519 + 867

25,800

4,386

25,800

= 0.1700 = 17 cM Incorrect MC

8474_08a5

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is analogous to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene D is related to the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

117

2,844

10,998

9,090

318

TOTAL =

23,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and M

distance =

½(2,844) + 3×(33 + 117)

23,400

1,422 + 450

23,400

1,872

23,400

= 0.0800 = 8 cM Incorrect distance =

½(2,844 + 9,090) + 3×(117)

23,400

5,967 + 351

23,400

6,318

23,400

= 0.2700 = 27 cM Incorrect distance =

½(9,090) + 3×(318)

23,400

4,545 + 954

23,400

5,499

23,400

= 0.2350 = 23.50 cM Incorrect distance =

½(9,090) + 3×(117 + 318)

23,400

4,545 + 1,305

23,400

5,850

23,400

= 0.2500 = 25 cM Correct distance =

½(2,844 + 9,090) + 3×(33 + 318)

23,400

5,967 + 1,053

23,400

7,020

23,400

= 0.3000 = 30 cM Incorrect MC

5181_a85c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is correlated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene N is associated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

1,938

2,730

11,419

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and N

distance =

½(2,730) + 3×(58)

16,200

1,365 + 174

16,200

1,539

16,200

= 0.0950 = 9.50 cM Incorrect distance =

½(1,938) + 3×(27 + 28)

16,200

969 + 165

16,200

1,134

16,200

= 0.0700 = 7 cM Incorrect distance =

½(1,938 + 2,730) + 3×(28 + 58)

16,200

2,334 + 258

16,200

2,592

16,200

= 0.1600 = 16 cM Incorrect distance =

½(2,730) + 3×(27 + 58)

16,200

1,365 + 255

16,200

1,620

16,200

= 0.1000 = 10 cM Correct distance =

½(1,938 + 2,730) + 3×(27 + 28 + 58)

16,200

2,334 + 339

16,200

2,673

16,200

= 0.1650 = 16.50 cM Incorrect MC

5a61_7afd

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is connected with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene J is linked with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene T is associated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

462

864

2,231

TOTAL =

3,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and T

distance =

½(462) + 3×(7 + 12)

3,600

231 + 57

3,600

288

3,600

= 0.0800 = 8 cM Incorrect distance =

½(864) + 3×(24)

3,600

432 + 72

3,600

504

3,600

= 0.1400 = 14 cM Incorrect distance =

½(462 + 864) + 3×(7 + 12)

3,600

663 + 57

3,600

720

3,600

= 0.2000 = 20 cM Incorrect distance =

½(864) + 3×(12 + 24)

3,600

432 + 108

3,600

540

3,600

= 0.1500 = 15 cM Correct distance =

½(462) + 3×(7 + 12 + 24)

3,600

231 + 129

3,600

360

3,600

= 0.1000 = 10 cM Incorrect MC

a381_8db9

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is associated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene T is affiliated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

144

3,510

310

4,782

7,373

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and K

distance =

½(4,782) + 3×(310)

16,200

2,391 + 930

16,200

3,321

16,200

= 0.2050 = 20.50 cM Incorrect distance =

½(3,510 + 4,782) + 3×(81 + 144 + 310)

16,200

4,146 + 1,605

16,200

5,751

16,200

= 0.3550 = 35.50 cM Incorrect distance =

½(3,510 + 4,782) + 3×(144 + 310)

16,200

4,146 + 1,362

16,200

5,508

16,200

= 0.3400 = 34 cM Incorrect distance =

½(3,510) + 3×(81 + 144)

16,200

1,755 + 675

16,200

2,430

16,200

= 0.1500 = 15 cM Correct distance =

½(4,782) + 3×(81 + 310)

16,200

2,391 + 1,173

16,200

3,564

16,200

= 0.2200 = 22 cM Incorrect MC

9aa1_e1d4

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is related to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is analogous to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

387

5,910

3,330

7,056

TOTAL =

16,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and N

distance =

½(3,330) + 3×(28 + 89)

16,800

1,665 + 351

16,800

2,016

16,800

= 0.1200 = 12 cM Incorrect distance =

½(5,910) + 3×(28 + 387)

16,800

2,955 + 1,245

16,800

4,200

16,800

= 0.2500 = 25 cM Correct distance =

½(3,330 + 5,910) + 3×(89 + 387)

16,800

4,620 + 1,428

16,800

6,048

16,800

= 0.3600 = 36 cM Incorrect distance =

½(3,330 + 5,910) + 3×(28)

16,800

4,620 + 84

16,800

4,704

16,800

= 0.2800 = 28 cM Incorrect distance =

½(3,330 + 5,910) + 3×(28 + 89 + 387)

16,800

4,620 + 1,512

16,800

6,132

16,800

= 0.3650 = 36.50 cM Incorrect MC

f517_d322

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is correlated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene N is analogous to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

1,086

2,430

1,668

109

TOTAL =

5,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and N

distance =

½(1,086 + 1,668) + 3×(63)

5,400

1,377 + 189

5,400

1,566

5,400

= 0.2900 = 29 cM Incorrect distance =

½(1,086 + 1,668) + 3×(44 + 109)

5,400

1,377 + 459

5,400

1,836

5,400

= 0.3400 = 34 cM Correct distance =

½(1,668) + 3×(109)

5,400

834 + 327

5,400

1,161

5,400

= 0.2150 = 21.50 cM Incorrect distance =

½(1,086) + 3×(44 + 63)

5,400

543 + 321

5,400

864

5,400

= 0.1600 = 16 cM Incorrect distance =

½(1,668) + 3×(63 + 109)

5,400

834 + 516

5,400

1,350

5,400

= 0.2500 = 25 cM Incorrect MC

b721_d089

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene X is linked with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

146

6,078

10,250

1,752

TOTAL =

18,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and X

distance =

½(6,078) + 3×(146)

18,300

3,039 + 438

18,300

3,477

18,300

= 0.1900 = 19 cM Incorrect distance =

½(1,752) + 3×(13 + 61)

18,300

876 + 222

18,300

1,098

18,300

= 0.0600 = 6 cM Incorrect distance =

½(6,078) + 3×(61 + 146)

18,300

3,039 + 621

18,300

3,660

18,300

= 0.2000 = 20 cM Correct distance =

½(1,752 + 6,078) + 3×(13 + 61 + 146)

18,300

3,915 + 660

18,300

4,575

18,300

= 0.2500 = 25 cM Incorrect distance =

½(1,752 + 6,078) + 3×(13 + 146)

18,300

3,915 + 477

18,300

4,392

18,300

= 0.2400 = 24 cM Incorrect MC

f148_9d39

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene J is correlated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

220

168

5,064

11,748

8,664

536

TOTAL =

26,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and J

distance =

½(5,064) + 3×(168)

26,400

2,532 + 504

26,400

3,036

26,400

= 0.1150 = 11.50 cM Incorrect distance =

½(8,664) + 3×(536)

26,400

4,332 + 1,608

26,400

5,940

26,400

= 0.2250 = 22.50 cM Incorrect distance =

½(8,664) + 3×(220 + 536)

26,400

4,332 + 2,268

26,400

6,600

26,400

= 0.2500 = 25 cM Incorrect distance =

½(5,064 + 8,664) + 3×(168 + 536)

26,400

6,864 + 2,112

26,400

8,976

26,400

= 0.3400 = 34 cM Incorrect distance =

½(5,064) + 3×(168 + 220)

26,400

2,532 + 1,164

26,400

3,696

26,400

= 0.1400 = 14 cM Correct MC

a148_4d54

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is associated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene H is affiliated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

222

6,312

12,201

9,858

709

TOTAL =

29,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and R

distance =

½(6,312 + 9,858) + 3×(98 + 222 + 709)

29,400

8,085 + 3,087

29,400

11,172

29,400

= 0.3800 = 38 cM Incorrect distance =

½(6,312) + 3×(222)

29,400

3,156 + 666

29,400

3,822

29,400

= 0.1300 = 13 cM Incorrect distance =

½(9,858) + 3×(98 + 709)

29,400

4,929 + 2,421

29,400

7,350

29,400

= 0.2500 = 25 cM Incorrect distance =

½(9,858) + 3×(709)

29,400

4,929 + 2,127

29,400

7,056

29,400

= 0.2400 = 24 cM Incorrect distance =

½(6,312 + 9,858) + 3×(222 + 709)

29,400

8,085 + 2,793

29,400

10,878

29,400

= 0.3700 = 37 cM Correct MC

30ff_4418

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is associated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene P is linked with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

108

2,592

156

3,024

6,060

TOTAL =

12,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and P

distance =

½(2,592) + 3×(60 + 108)

12,000

1,296 + 504

12,000

1,800

12,000

= 0.1500 = 15 cM Correct distance =

½(2,592 + 3,024) + 3×(108 + 156)

12,000

2,808 + 792

12,000

3,600

12,000

= 0.3000 = 30 cM Incorrect distance =

½(3,024) + 3×(108 + 156)

12,000

1,512 + 792

12,000

2,304

12,000

= 0.1920 = 19.20 cM Incorrect distance =

½(3,024) + 3×(60 + 156)

12,000

1,512 + 648

12,000

2,160

12,000

= 0.1800 = 18 cM Incorrect distance =

½(2,592 + 3,024) + 3×(60)

12,000

2,808 + 180

12,000

2,988

12,000

= 0.2490 = 24.90 cM Incorrect MC

3ce5_f5b5

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,572

8,250

4,998

142

TOTAL =

15,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and W

distance =

½(1,572) + 3×(13 + 25)

15,000

786 + 114

15,000

900

15,000

= 0.0600 = 6 cM Incorrect distance =

½(1,572) + 3×(13)

15,000

786 + 39

15,000

825

15,000

= 0.0550 = 5.50 cM Incorrect distance =

½(4,998) + 3×(25 + 142)

15,000

2,499 + 501

15,000

3,000

15,000

= 0.2000 = 20 cM Correct distance =

½(1,572 + 4,998) + 3×(13 + 25 + 142)

15,000

3,285 + 540

15,000

3,825

15,000

= 0.2550 = 25.50 cM Incorrect distance =

½(1,572 + 4,998) + 3×(13 + 142)

15,000

3,285 + 465

15,000

3,750

15,000

= 0.2500 = 25 cM Incorrect MC

53ad_d532

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is correlated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene J is related to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

133

4,548

369

7,020

12,149

TOTAL =

24,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and M

distance =

½(4,548) + 3×(81 + 133)

24,300

2,274 + 642

24,300

2,916

24,300

= 0.1200 = 12 cM Correct distance =

½(4,548) + 3×(133)

24,300

2,274 + 399

24,300

2,673

24,300

= 0.1100 = 11 cM Incorrect distance =

½(4,548 + 7,020) + 3×(133 + 369)

24,300

5,784 + 1,506

24,300

7,290

24,300

= 0.3000 = 30 cM Incorrect distance =

½(7,020) + 3×(369)

24,300

3,510 + 1,107

24,300

4,617

24,300

= 0.1900 = 19 cM Incorrect distance =

½(4,548 + 7,020) + 3×(81 + 133 + 369)

24,300

5,784 + 1,749

24,300

7,533

24,300

= 0.3100 = 31 cM Incorrect MC

f8cc_4653

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is linked with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene E is analogous to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

762

2,927

1,044

TOTAL =

4,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and E

distance =

½(1,044) + 3×(34)

4,800

522 + 102

4,800

624

4,800

= 0.1300 = 13 cM Incorrect distance =

½(762 + 1,044) + 3×(16 + 17 + 34)

4,800

903 + 201

4,800

1,104

4,800

= 0.2300 = 23 cM Incorrect distance =

½(762) + 3×(17)

4,800

381 + 51

4,800

432

4,800

= 0.0900 = 9 cM Incorrect distance =

½(762) + 3×(16 + 17)

4,800

381 + 99

4,800

480

4,800

= 0.1000 = 10 cM Correct distance =

½(762 + 1,044) + 3×(17 + 34)

4,800

903 + 153

4,800

1,056

4,800

= 0.2200 = 22 cM Incorrect MC

45a1_9eca

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is correlated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene K is associated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

2,166

2,527

612

TOTAL =

5,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and K

distance =

½(2,166) + 3×(71)

5,400

1,083 + 213

5,400

1,296

5,400

= 0.2400 = 24 cM Incorrect distance =

½(612) + 3×(6)

5,400

306 + 18

5,400

324

5,400

= 0.0600 = 6 cM Incorrect distance =

½(612) + 3×(6 + 18)

5,400

306 + 72

5,400

378

5,400

= 0.0700 = 7 cM Correct distance =

½(612 + 2,166) + 3×(6 + 71)

5,400

1,389 + 231

5,400

1,620

5,400

= 0.3000 = 30 cM Incorrect distance =

½(2,166) + 3×(18 + 71)

5,400

1,083 + 267

5,400

1,350

5,400

= 0.2500 = 25 cM Incorrect MC

f57d_6665

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is correlated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene E is connected with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene X is correlated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

7,576

1,842

6,498

213

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and X

distance =

½(1,842 + 6,498) + 3×(17 + 213)

16,200

4,170 + 690

16,200

4,860

16,200

= 0.3000 = 30 cM Incorrect distance =

½(6,498) + 3×(54 + 213)

16,200

3,249 + 801

16,200

4,050

16,200

= 0.2500 = 25 cM Incorrect distance =

½(1,842 + 6,498) + 3×(17 + 54 + 213)

16,200

4,170 + 852

16,200

5,022

16,200

= 0.3100 = 31 cM Incorrect distance =

½(1,842) + 3×(17 + 54)

16,200

921 + 213

16,200

1,134

16,200

= 0.0700 = 7 cM Correct distance =

½(6,498) + 3×(213)

16,200

3,249 + 639

16,200

3,888

16,200

= 0.2400 = 24 cM Incorrect MC

516b_ab01

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is related to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene K is associated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

2,172

5,380

4,410

249

TOTAL =

12,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and W

distance =

½(4,410) + 3×(41 + 249)

12,300

2,205 + 870

12,300

3,075

12,300

= 0.2500 = 25 cM Correct distance =

½(2,172 + 4,410) + 3×(41 + 48 + 249)

12,300

3,291 + 1,014

12,300

4,305

12,300

= 0.3500 = 35 cM Incorrect distance =

½(4,410) + 3×(249)

12,300

2,205 + 747

12,300

2,952

12,300

= 0.2400 = 24 cM Incorrect distance =

½(2,172) + 3×(41 + 48)

12,300

1,086 + 267

12,300

1,353

12,300

= 0.1100 = 11 cM Incorrect distance =

½(2,172) + 3×(48)

12,300

1,086 + 144

12,300

1,230

12,300

= 0.1000 = 10 cM Incorrect MC

2494_ee42

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is linked with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene E is connected with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

388

6,120

8,592

3,768

140

192

TOTAL =

19,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and E

distance =

½(3,768 + 6,120) + 3×(140 + 388)

19,200

4,944 + 1,584

19,200

6,528

19,200

= 0.3400 = 34 cM Incorrect distance =

½(3,768) + 3×(140)

19,200

1,884 + 420

19,200

2,304

19,200

= 0.1200 = 12 cM Incorrect distance =

½(6,120) + 3×(388)

19,200

3,060 + 1,164

19,200

4,224

19,200

= 0.2200 = 22 cM Incorrect distance =

½(6,120) + 3×(192 + 388)

19,200

3,060 + 1,740

19,200

4,800

19,200

= 0.2500 = 25 cM Incorrect distance =

½(3,768) + 3×(140 + 192)

19,200

1,884 + 996

19,200

2,880

19,200

= 0.1500 = 15 cM Correct MC

0b9c_67f3

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is analogous to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene J is correlated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.

Set #

Tetrad Genotypes

Progeny
Count

201

4,038

1,842

5,246

TOTAL =

11,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and J

distance =

½(1,842 + 4,038) + 3×(35 + 201)

11,400

2,940 + 708

11,400

3,648

11,400

= 0.3200 = 32 cM Incorrect distance =

½(1,842 + 4,038) + 3×(35 + 38 + 201)

11,400

2,940 + 822

11,400

3,762

11,400

= 0.3300 = 33 cM Incorrect distance =

½(1,842) + 3×(35 + 38)

11,400

921 + 219

11,400

1,140

11,400

= 0.1000 = 10 cM Correct distance =

½(4,038) + 3×(38 + 201)

11,400

2,019 + 717

11,400

2,736

11,400

= 0.2400 = 24 cM Incorrect distance =

½(1,842) + 3×(35)

11,400

921 + 105

11,400

1,026

11,400

= 0.0900 = 9 cM Incorrect MC

cf16_1b42

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene R is linked with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene Y is correlated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,866

12,840

9,030

175

TOTAL =

24,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes R and Y

distance =

½(1,866) + 3×(9 + 80)

24,000

933 + 267

24,000

1,200

24,000

= 0.0500 = 5 cM Incorrect distance =

½(1,866 + 9,030) + 3×(9 + 175)

24,000

5,448 + 552

24,000

6,000

24,000

= 0.2500 = 25 cM Incorrect distance =

½(9,030) + 3×(80 + 175)

24,000

4,515 + 765

24,000

5,280

24,000

= 0.2200 = 22 cM Correct distance =

½(1,866) + 3×(9)

24,000

933 + 27

24,000

960

24,000

= 0.0400 = 4 cM Incorrect distance =

½(9,030) + 3×(175)

24,000

4,515 + 525

24,000

5,040

24,000

= 0.2100 = 21 cM Incorrect MC

e7c2_4abf

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is analogous to the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene K is related to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

112

1,392

2,016

1,152

TOTAL =

4,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and K

distance =

½(1,152) + 3×(56 + 72 + 112)

4,800

576 + 720

4,800

1,296

4,800

= 0.2700 = 27 cM Incorrect distance =

½(1,152 + 1,392) + 3×(56)

4,800

1,272 + 168

4,800

1,440

4,800

= 0.3000 = 30 cM Incorrect distance =

½(1,392) + 3×(72)

4,800

696 + 216

4,800

912

4,800

= 0.1900 = 19 cM Incorrect distance =

½(1,152 + 1,392) + 3×(72 + 112)

4,800

1,272 + 552

4,800

1,824

4,800

= 0.3800 = 38 cM Correct distance =

½(1,152) + 3×(56 + 72)

4,800

576 + 384

4,800

960

4,800

= 0.2000 = 20 cM Incorrect MC

f35e_cfce

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is connected with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

1,938

219

9,120

10,876

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and R

distance =

½(1,938) + 3×(10 + 37)

22,200

969 + 141

22,200

1,110

22,200

= 0.0500 = 5 cM Incorrect distance =

½(1,938 + 9,120) + 3×(10 + 37 + 219)

22,200

5,529 + 798

22,200

6,327

22,200

= 0.2850 = 28.50 cM Incorrect distance =

½(1,938) + 3×(10)

22,200

969 + 30

22,200

999

22,200

= 0.0450 = 4.50 cM Incorrect distance =

½(1,938 + 9,120) + 3×(10 + 219)

22,200

5,529 + 687

22,200

6,216

22,200

= 0.2800 = 28 cM Incorrect distance =

½(9,120) + 3×(37 + 219)

22,200

4,560 + 768

22,200

5,328

22,200

= 0.2400 = 24 cM Correct MC

46fc_7e3b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is connected with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene D is associated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

155

3,390

1,470

4,510

TOTAL =

9,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and W

distance =

½(1,470 + 3,390) + 3×(27 + 155)

9,600

2,430 + 546

9,600

2,976

9,600

= 0.3100 = 31 cM Incorrect distance =

½(3,390) + 3×(48 + 155)

9,600

1,695 + 609

9,600

2,304

9,600

= 0.2400 = 24 cM Correct distance =

½(1,470) + 3×(48 + 155)

9,600

735 + 609

9,600

1,344

9,600

= 0.1400 = 14 cM Incorrect distance =

½(3,390) + 3×(27 + 48)

9,600

1,695 + 225

9,600

1,920

9,600

= 0.2000 = 20 cM Incorrect distance =

½(1,470) + 3×(27 + 48)

9,600

735 + 225

9,600

960

9,600

= 0.1000 = 10 cM Incorrect MC

e909_3b6a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene N is affiliated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene Y is linked with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

834

2,970

5,710

TOTAL =

9,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and N

distance =

½(2,970) + 3×(16 + 65)

9,600

1,485 + 243

9,600

1,728

9,600

= 0.1800 = 18 cM Incorrect distance =

½(834 + 2,970) + 3×(5 + 16 + 65)

9,600

1,902 + 258

9,600

2,160

9,600

= 0.2250 = 22.50 cM Incorrect distance =

½(834) + 3×(5 + 16)

9,600

417 + 63

9,600

480

9,600

= 0.0500 = 5 cM Incorrect distance =

½(834 + 2,970) + 3×(5 + 65)

9,600

1,902 + 210

9,600

2,112

9,600

= 0.2200 = 22 cM Correct distance =

½(2,970) + 3×(65)

9,600

1,485 + 195

9,600

1,680

9,600

= 0.1750 = 17.50 cM Incorrect MC

deec_5db5

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is linked with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene M is connected with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

3,972

446

10,860

144

13,320

TOTAL =

28,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and M

distance =

½(3,972) + 3×(58)

28,800

1,986 + 174

28,800

2,160

28,800

= 0.0750 = 7.50 cM Incorrect distance =

½(3,972 + 10,860) + 3×(58 + 144 + 446)

28,800

7,416 + 1,944

28,800

9,360

28,800

= 0.3250 = 32.50 cM Incorrect distance =

½(3,972) + 3×(58 + 144)

28,800

1,986 + 606

28,800

2,592

28,800

= 0.0900 = 9 cM Incorrect distance =

½(3,972 + 10,860) + 3×(58 + 446)

28,800

7,416 + 1,512

28,800

8,928

28,800

= 0.3100 = 31 cM Incorrect distance =

½(10,860) + 3×(144 + 446)

28,800

5,430 + 1,770

28,800

7,200

28,800

= 0.2500 = 25 cM Correct MC

8ea4_1fa1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is associated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene X is connected with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

435

11,356

6,252

7,056

437

564

TOTAL =

26,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes X and Y

distance =

½(6,252) + 3×(437)

26,100

3,126 + 1,311

26,100

4,437

26,100

= 0.1700 = 17 cM Incorrect distance =

½(6,252 + 7,056) + 3×(437 + 564)

26,100

6,654 + 3,003

26,100

9,657

26,100

= 0.3700 = 37 cM Incorrect distance =

½(6,252 + 7,056) + 3×(435 + 437 + 564)

26,100

6,654 + 4,308

26,100

10,962

26,100

= 0.4200 = 42 cM Incorrect distance =

½(7,056) + 3×(435 + 564)

26,100

3,528 + 2,997

26,100

6,525

26,100

= 0.2500 = 25 cM Correct distance =

½(6,252) + 3×(435 + 437)

26,100

3,126 + 2,616

26,100

5,742

26,100

= 0.2200 = 22 cM Incorrect MC

127d_f16b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is analogous to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene T is affiliated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

503

7,062

649

7,914

432

12,240

TOTAL =

28,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and T

distance =

½(7,914) + 3×(649)

28,800

3,957 + 1,947

28,800

5,904

28,800

= 0.2050 = 20.50 cM Incorrect distance =

½(7,062) + 3×(503)

28,800

3,531 + 1,509

28,800

5,040

28,800

= 0.1750 = 17.50 cM Incorrect distance =

½(7,062 + 7,914) + 3×(503 + 649)

28,800

7,488 + 3,456

28,800

10,944

28,800

= 0.3800 = 38 cM Correct distance =

½(7,914) + 3×(432 + 649)

28,800

3,957 + 3,243

28,800

7,200

28,800

= 0.2500 = 25 cM Incorrect distance =

½(7,062) + 3×(432 + 503)

28,800

3,531 + 2,805

28,800

6,336

28,800

= 0.2200 = 22 cM Incorrect MC

935f_afbe

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene C is analogous to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene P is associated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

282

440

6,948

11,562

8,280

688

TOTAL =

28,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and P

distance =

½(6,948 + 8,280) + 3×(440 + 688)

28,200

7,614 + 3,384

28,200

10,998

28,200

= 0.3900 = 39 cM Correct distance =

½(6,948 + 8,280) + 3×(282)

28,200

7,614 + 846

28,200

8,460

28,200

= 0.3000 = 30 cM Incorrect distance =

½(8,280) + 3×(688)

28,200

4,140 + 2,064

28,200

6,204

28,200

= 0.2200 = 22 cM Incorrect distance =

½(6,948) + 3×(282 + 440)

28,200

3,474 + 2,166

28,200

5,640

28,200

= 0.2000 = 20 cM Incorrect distance =

½(8,280) + 3×(282 + 688)

28,200

4,140 + 2,910

28,200

7,050

28,200

= 0.2500 = 25 cM Incorrect MC

a63f_ce22

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene F is related to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.

Set #

Tetrad Genotypes

Progeny
Count

1,530

171

2,922

3,696

TOTAL =

8,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and F

distance =

½(1,530 + 2,922) + 3×(42)

8,400

2,226 + 126

8,400

2,352

8,400

= 0.2800 = 28 cM Incorrect distance =

½(1,530 + 2,922) + 3×(39 + 42 + 171)

8,400

2,226 + 756

8,400

2,982

8,400

= 0.3550 = 35.50 cM Incorrect distance =

½(2,922) + 3×(42 + 171)

8,400

1,461 + 639

8,400

2,100

8,400

= 0.2500 = 25 cM Incorrect distance =

½(1,530) + 3×(39 + 42)

8,400

765 + 243

8,400

1,008

8,400

= 0.1200 = 12 cM Incorrect distance =

½(1,530 + 2,922) + 3×(39 + 171)

8,400

2,226 + 630

8,400

2,856

8,400

= 0.3400 = 34 cM Correct MC

213d_0839

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is analogous to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene P is related to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

270

7,650

4,416

4,944

314

406

TOTAL =

18,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and P

distance =

½(4,416 + 4,944) + 3×(270)

18,000

4,680 + 810

18,000

5,490

18,000

= 0.3050 = 30.50 cM Incorrect distance =

½(4,944) + 3×(270 + 406)

18,000

2,472 + 2,028

18,000

4,500

18,000

= 0.2500 = 25 cM Incorrect distance =

½(4,416 + 4,944) + 3×(270 + 314 + 406)

18,000

4,680 + 2,970

18,000

7,650

18,000

= 0.4250 = 42.50 cM Incorrect distance =

½(4,416) + 3×(270 + 314)

18,000

2,208 + 1,752

18,000

3,960

18,000

= 0.2200 = 22 cM Correct distance =

½(4,416 + 4,944) + 3×(314 + 406)

18,000

4,680 + 2,160

18,000

6,840

18,000

= 0.3800 = 38 cM Incorrect MC

2d73_87ce

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is correlated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene J is affiliated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene M is associated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

408

6,672

380

637

8,148

12,255

TOTAL =

28,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and M

distance =

½(8,148) + 3×(637)

28,500

4,074 + 1,911

28,500

5,985

28,500

= 0.2100 = 21 cM Incorrect distance =

½(6,672 + 8,148) + 3×(380)

28,500

7,410 + 1,140

28,500

8,550

28,500

= 0.3000 = 30 cM Incorrect distance =

½(8,148) + 3×(380 + 637)

28,500

4,074 + 3,051

28,500

7,125

28,500

= 0.2500 = 25 cM Incorrect distance =

½(6,672 + 8,148) + 3×(408 + 637)

28,500

7,410 + 3,135

28,500

10,545

28,500

= 0.3700 = 37 cM Correct distance =

½(6,672) + 3×(408)

28,500

3,336 + 1,224

28,500

4,560

28,500

= 0.1600 = 16 cM Incorrect MC

8e71_ad29

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene N is related to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene P is associated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene R is affiliated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

3,684

111

166

4,998

13,152

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and R

distance =

½(3,684) + 3×(89)

22,200

1,842 + 267

22,200

2,109

22,200

= 0.0950 = 9.50 cM Incorrect distance =

½(4,998) + 3×(111 + 166)

22,200

2,499 + 831

22,200

3,330

22,200

= 0.1500 = 15 cM Correct distance =

½(3,684) + 3×(89 + 111)

22,200

1,842 + 600

22,200

2,442

22,200

= 0.1100 = 11 cM Incorrect distance =

½(3,684 + 4,998) + 3×(89 + 111 + 166)

22,200

4,341 + 1,098

22,200

5,439

22,200

= 0.2450 = 24.50 cM Incorrect distance =

½(3,684 + 4,998) + 3×(89 + 166)

22,200

4,341 + 765

22,200

5,106

22,200

= 0.2300 = 23 cM Incorrect MC

fe82_54b6

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is affiliated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene F is associated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.

Set #

Tetrad Genotypes

Progeny
Count

187

129

4,836

14,585

7,956

357

TOTAL =

28,050

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and H

distance =

½(4,836) + 3×(129)

28,050

2,418 + 387

28,050

2,805

28,050

= 0.1000 = 10 cM Incorrect distance =

½(7,956) + 3×(357)

28,050

3,978 + 1,071

28,050

5,049

28,050

= 0.1800 = 18 cM Incorrect distance =

½(4,836) + 3×(129 + 187)

28,050

2,418 + 948

28,050

3,366

28,050

= 0.1200 = 12 cM Incorrect distance =

½(4,836 + 7,956) + 3×(129 + 187 + 357)

28,050

6,396 + 2,019

28,050

8,415

28,050

= 0.3000 = 30 cM Incorrect distance =

½(7,956) + 3×(187 + 357)

28,050

3,978 + 1,632

28,050

5,610

28,050

= 0.2000 = 20 cM Correct MC

152f_f8b3

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

3,762

222

6,672

16,835

TOTAL =

27,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and P

distance =

½(3,762 + 6,672) + 3×(46 + 63 + 222)

27,600

5,217 + 993

27,600

6,210

27,600

= 0.2250 = 22.50 cM Incorrect distance =

½(3,762 + 6,672) + 3×(63 + 222)

27,600

5,217 + 855

27,600

6,072

27,600

= 0.2200 = 22 cM Correct distance =

½(3,762) + 3×(46 + 63)

27,600

1,881 + 327

27,600

2,208

27,600

= 0.0800 = 8 cM Incorrect distance =

½(6,672) + 3×(46 + 222)

27,600

3,336 + 804

27,600

4,140

27,600

= 0.1500 = 15 cM Incorrect distance =

½(3,762) + 3×(63)

27,600

1,881 + 189

27,600

2,070

27,600

= 0.0750 = 7.50 cM Incorrect MC

197a_bf7a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene R is correlated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene X is analogous to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is linked with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

596

7,464

12,006

6,612

462

460

TOTAL =

27,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes X and Y

distance =

½(7,464) + 3×(460 + 596)

27,600

3,732 + 3,168

27,600

6,900

27,600

= 0.2500 = 25 cM Correct distance =

½(6,612) + 3×(460 + 462)

27,600

3,306 + 2,766

27,600

6,072

27,600

= 0.2200 = 22 cM Incorrect distance =

½(6,612 + 7,464) + 3×(462 + 596)

27,600

7,038 + 3,174

27,600

10,212

27,600

= 0.3700 = 37 cM Incorrect distance =

½(6,612) + 3×(462)

27,600

3,306 + 1,386

27,600

4,692

27,600

= 0.1700 = 17 cM Incorrect distance =

½(6,612 + 7,464) + 3×(460 + 462 + 596)

27,600

7,038 + 4,554

27,600

11,592

27,600

= 0.4200 = 42 cM Incorrect MC

78d0_852a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is affiliated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene W is correlated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

136

1,914

176

2,142

117

3,315

TOTAL =

7,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and N

distance =

½(2,142) + 3×(176)

7,800

1,071 + 528

7,800

1,599

7,800

= 0.2050 = 20.50 cM Incorrect distance =

½(1,914) + 3×(117 + 136)

7,800

957 + 759

7,800

1,716

7,800

= 0.2200 = 22 cM Incorrect distance =

½(1,914 + 2,142) + 3×(136 + 176)

7,800

2,028 + 936

7,800

2,964

7,800

= 0.3800 = 38 cM Correct distance =

½(2,142) + 3×(117 + 176)

7,800

1,071 + 879

7,800

1,950

7,800

= 0.2500 = 25 cM Incorrect distance =

½(1,914 + 2,142) + 3×(117 + 136 + 176)

7,800

2,028 + 1,287

7,800

3,315

7,800

= 0.4250 = 42.50 cM Incorrect MC

b78f_2a6e

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is analogous to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene W is affiliated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

162

1,980

3,060

1,764

108

126

TOTAL =

7,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and W

distance =

½(1,764 + 1,980) + 3×(126 + 162)

7,200

1,872 + 864

7,200

2,736

7,200

= 0.3800 = 38 cM Incorrect distance =

½(1,980) + 3×(126)

7,200

990 + 378

7,200

1,368

7,200

= 0.1900 = 19 cM Incorrect distance =

½(1,980) + 3×(108 + 162)

7,200

990 + 810

7,200

1,800

7,200

= 0.2500 = 25 cM Correct distance =

½(1,764) + 3×(126)

7,200

882 + 378

7,200

1,260

7,200

= 0.1750 = 17.50 cM Incorrect distance =

½(1,764) + 3×(108 + 126)

7,200

882 + 702

7,200

1,584

7,200

= 0.2200 = 22 cM Incorrect MC

ccee_7a77

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is associated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.

Set #

Tetrad Genotypes

Progeny
Count

2,430

4,453

1,332

TOTAL =

8,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and D

distance =

½(1,332 + 2,430) + 3×(30 + 99)

8,400

1,881 + 387

8,400

2,268

8,400

= 0.2700 = 27 cM Correct distance =

½(1,332 + 2,430) + 3×(30 + 56 + 99)

8,400

1,881 + 555

8,400

2,436

8,400

= 0.2900 = 29 cM Incorrect distance =

½(1,332) + 3×(30 + 56)

8,400

666 + 258

8,400

924

8,400

= 0.1100 = 11 cM Incorrect distance =

½(1,332) + 3×(30)

8,400

666 + 90

8,400

756

8,400

= 0.0900 = 9 cM Incorrect distance =

½(2,430) + 3×(99)

8,400

1,215 + 297

8,400

1,512

8,400

= 0.1800 = 18 cM Incorrect MC

3308_a334

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

3,955

2,124

2,802

111

215

TOTAL =

9,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and K

distance =

½(2,124 + 2,802) + 3×(93 + 111 + 215)

9,300

2,463 + 1,257

9,300

3,720

9,300

= 0.4000 = 40 cM Incorrect distance =

½(2,802) + 3×(93 + 215)

9,300

1,401 + 924

9,300

2,325

9,300

= 0.2500 = 25 cM Incorrect distance =

½(2,802) + 3×(215)

9,300

1,401 + 645

9,300

2,046

9,300

= 0.2200 = 22 cM Incorrect distance =

½(2,124) + 3×(111)

9,300

1,062 + 333

9,300

1,395

9,300

= 0.1500 = 15 cM Incorrect distance =

½(2,124 + 2,802) + 3×(111 + 215)

9,300

2,463 + 978

9,300

3,441

9,300

= 0.3700 = 37 cM Correct MC

8625_8471

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is analogous to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene P is affiliated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

137

5,112

594

9,078

10,836

TOTAL =

25,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and W

distance =

½(5,112 + 9,078) + 3×(137 + 594)

25,800

7,095 + 2,193

25,800

9,288

25,800

= 0.3600 = 36 cM Incorrect distance =

½(5,112) + 3×(43 + 137)

25,800

2,556 + 540

25,800

3,096

25,800

= 0.1200 = 12 cM Correct distance =

½(5,112 + 9,078) + 3×(43)

25,800

7,095 + 129

25,800

7,224

25,800

= 0.2800 = 28 cM Incorrect distance =

½(9,078) + 3×(43 + 594)

25,800

4,539 + 1,911

25,800

6,450

25,800

= 0.2500 = 25 cM Incorrect distance =

½(5,112) + 3×(137)

25,800

2,556 + 411

25,800

2,967

25,800

= 0.1150 = 11.50 cM Incorrect MC

ea31_64cf

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is linked with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene K is associated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene X is associated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

112

4,320

1,926

2,970

193

TOTAL =

9,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and X

distance =

½(1,926 + 2,970) + 3×(112)

9,600

2,448 + 336

9,600

2,784

9,600

= 0.2900 = 29 cM Incorrect distance =

½(1,926) + 3×(79 + 112)

9,600

963 + 573

9,600

1,536

9,600

= 0.1600 = 16 cM Incorrect distance =

½(1,926 + 2,970) + 3×(79 + 193)

9,600

2,448 + 816

9,600

3,264

9,600

= 0.3400 = 34 cM Incorrect distance =

½(2,970) + 3×(112 + 193)

9,600

1,485 + 915

9,600

2,400

9,600

= 0.2500 = 25 cM Correct distance =

½(1,926) + 3×(79)

9,600

963 + 237

9,600

1,200

9,600

= 0.1250 = 12.50 cM Incorrect MC

5d0a_8d24

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene B is connected with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene N is correlated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

200

215

3,510

6,450

4,290

335

TOTAL =

15,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and N

distance =

½(3,510 + 4,290) + 3×(200 + 215 + 335)

15,000

3,900 + 2,250

15,000

6,150

15,000

= 0.4100 = 41 cM Incorrect distance =

½(3,510) + 3×(200 + 215)

15,000

1,755 + 1,245

15,000

3,000

15,000

= 0.2000 = 20 cM Incorrect distance =

½(4,290) + 3×(200 + 335)

15,000

2,145 + 1,605

15,000

3,750

15,000

= 0.2500 = 25 cM Incorrect distance =

½(3,510 + 4,290) + 3×(215 + 335)

15,000

3,900 + 1,650

15,000

5,550

15,000

= 0.3700 = 37 cM Correct distance =

½(4,290) + 3×(335)

15,000

2,145 + 1,005

15,000

3,150

15,000

= 0.2100 = 21 cM Incorrect MC

eba8_ecd4

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is related to the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene T is linked with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,950

6,885

4,368

172

TOTAL =

13,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and Y

distance =

½(1,950 + 4,368) + 3×(35 + 172)

13,500

3,159 + 621

13,500

3,780

13,500

= 0.2800 = 28 cM Correct distance =

½(1,950) + 3×(35 + 90)

13,500

975 + 375

13,500

1,350

13,500

= 0.1000 = 10 cM Incorrect distance =

½(4,368) + 3×(172)

13,500

2,184 + 516

13,500

2,700

13,500

= 0.2000 = 20 cM Incorrect distance =

½(1,950 + 4,368) + 3×(35 + 90 + 172)

13,500

3,159 + 891

13,500

4,050

13,500

= 0.3000 = 30 cM Incorrect distance =

½(4,368) + 3×(90 + 172)

13,500

2,184 + 786

13,500

2,970

13,500

= 0.2200 = 22 cM Incorrect MC

ceef_b79c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is analogous to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene H is related to the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene K is related to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

385

8,490

3,630

11,220

200

TOTAL =

24,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and H

distance =

½(3,630) + 3×(75 + 200)

24,000

1,815 + 825

24,000

2,640

24,000

= 0.1100 = 11 cM Incorrect distance =

½(3,630 + 8,490) + 3×(75 + 385)

24,000

6,060 + 1,380

24,000

7,440

24,000

= 0.3100 = 31 cM Correct distance =

½(8,490) + 3×(385)

24,000

4,245 + 1,155

24,000

5,400

24,000

= 0.2250 = 22.50 cM Incorrect distance =

½(8,490) + 3×(200 + 385)

24,000

4,245 + 1,755

24,000

6,000

24,000

= 0.2500 = 25 cM Incorrect distance =

½(3,630 + 8,490) + 3×(75 + 200 + 385)

24,000

6,060 + 1,980

24,000

8,040

24,000

= 0.3350 = 33.50 cM Incorrect MC

53e7_5d59

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is connected with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene E is linked with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene J is affiliated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.

Set #

Tetrad Genotypes

Progeny
Count

1,524

8,224

7,434

182

TOTAL =

17,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and J

distance =

½(1,524) + 3×(7 + 29)

17,400

762 + 108

17,400

870

17,400

= 0.0500 = 5 cM Incorrect distance =

½(1,524 + 7,434) + 3×(7 + 182)

17,400

4,479 + 567

17,400

5,046

17,400

= 0.2900 = 29 cM Correct distance =

½(1,524) + 3×(7)

17,400

762 + 21

17,400

783

17,400

= 0.0450 = 4.50 cM Incorrect distance =

½(7,434) + 3×(29 + 182)

17,400

3,717 + 633

17,400

4,350

17,400

= 0.2500 = 25 cM Incorrect distance =

½(1,524 + 7,434) + 3×(7 + 29 + 182)

17,400

4,479 + 654

17,400

5,133

17,400

= 0.2950 = 29.50 cM Incorrect MC

3751_5c65

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is associated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene P is linked with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

4,140

1,452

3,192

158

TOTAL =

9,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and W

distance =

½(3,192) + 3×(30 + 158)

9,000

1,596 + 564

9,000

2,160

9,000

= 0.2400 = 24 cM Incorrect distance =

½(1,452 + 3,192) + 3×(28 + 158)

9,000

2,322 + 558

9,000

2,880

9,000

= 0.3200 = 32 cM Incorrect distance =

½(1,452) + 3×(28 + 30)

9,000

726 + 174

9,000

900

9,000

= 0.1000 = 10 cM Correct distance =

½(1,452 + 3,192) + 3×(28 + 30 + 158)

9,000

2,322 + 648

9,000

2,970

9,000

= 0.3300 = 33 cM Incorrect distance =

½(1,452) + 3×(28)

9,000

726 + 84

9,000

810

9,000

= 0.0900 = 9 cM Incorrect MC

cf51_2dcf

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene N is analogous to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene R is affiliated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

286

4,620

5,676

2,508

TOTAL =

13,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and R

distance =

½(4,620) + 3×(66)

13,200

2,310 + 198

13,200

2,508

13,200

= 0.1900 = 19 cM Incorrect distance =

½(2,508 + 4,620) + 3×(44 + 66 + 286)

13,200

3,564 + 1,188

13,200

4,752

13,200

= 0.3600 = 36 cM Incorrect distance =

½(2,508) + 3×(286)

13,200

1,254 + 858

13,200

2,112

13,200

= 0.1600 = 16 cM Incorrect distance =

½(2,508 + 4,620) + 3×(66 + 286)

13,200

3,564 + 1,056

13,200

4,620

13,200

= 0.3500 = 35 cM Correct distance =

½(2,508) + 3×(66)

13,200

1,254 + 198

13,200

1,452

13,200

= 0.1100 = 11 cM Incorrect MC

f1b1_cf28

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is related to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene W is affiliated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

2,712

104

296

5,400

7,020

TOTAL =

15,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and W

distance =

½(5,400) + 3×(104 + 296)

15,600

2,700 + 1,200

15,600

3,900

15,600

= 0.2500 = 25 cM Incorrect distance =

½(2,712 + 5,400) + 3×(104)

15,600

4,056 + 312

15,600

4,368

15,600

= 0.2800 = 28 cM Incorrect distance =

½(2,712 + 5,400) + 3×(68 + 104 + 296)

15,600

4,056 + 1,404

15,600

5,460

15,600

= 0.3500 = 35 cM Incorrect distance =

½(2,712) + 3×(68 + 104)

15,600

1,356 + 516

15,600

1,872

15,600

= 0.1200 = 12 cM Incorrect distance =

½(2,712 + 5,400) + 3×(68 + 296)

15,600

4,056 + 1,092

15,600

5,148

15,600

= 0.3300 = 33 cM Correct MC

1fb6_17ac

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene P is affiliated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

380

8,052

3,954

12,053

TOTAL =

24,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and N

distance =

½(8,052) + 3×(82 + 380)

24,600

4,026 + 1,386

24,600

5,412

24,600

= 0.2200 = 22 cM Incorrect distance =

½(3,954) + 3×(79)

24,600

1,977 + 237

24,600

2,214

24,600

= 0.0900 = 9 cM Incorrect distance =

½(8,052) + 3×(380)

24,600

4,026 + 1,140

24,600

5,166

24,600

= 0.2100 = 21 cM Incorrect distance =

½(3,954 + 8,052) + 3×(79 + 380)

24,600

6,003 + 1,377

24,600

7,380

24,600

= 0.3000 = 30 cM Correct distance =

½(3,954) + 3×(79 + 82)

24,600

1,977 + 483

24,600

2,460

24,600

= 0.1000 = 10 cM Incorrect MC

d07f_d5a7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is connected with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene N is related to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene T is connected with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

366

1,014

2,791

TOTAL =

4,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and N

distance =

½(366) + 3×(2)

4,200

183 + 6

4,200

189

4,200

= 0.0450 = 4.50 cM Incorrect distance =

½(1,014) + 3×(20)

4,200

507 + 60

4,200

567

4,200

= 0.1350 = 13.50 cM Incorrect distance =

½(366) + 3×(2 + 7)

4,200

183 + 27

4,200

210

4,200

= 0.0500 = 5 cM Incorrect distance =

½(366 + 1,014) + 3×(2 + 20)

4,200

690 + 66

4,200

756

4,200

= 0.1800 = 18 cM Correct distance =

½(1,014) + 3×(7 + 20)

4,200

507 + 81

4,200

588

4,200

= 0.1400 = 14 cM Incorrect MC

2d19_5f53

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is correlated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene M is analogous to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene X is associated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

1,554

4,272

3,534

179

TOTAL =

9,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and X

distance =

½(1,554 + 3,534) + 3×(29 + 32 + 179)

9,600

2,544 + 720

9,600

3,264

9,600

= 0.3400 = 34 cM Incorrect distance =

½(1,554) + 3×(29)

9,600

777 + 87

9,600

864

9,600

= 0.0900 = 9 cM Incorrect distance =

½(1,554) + 3×(29 + 32)

9,600

777 + 183

9,600

960

9,600

= 0.1000 = 10 cM Incorrect distance =

½(1,554 + 3,534) + 3×(29 + 179)

9,600

2,544 + 624

9,600

3,168

9,600

= 0.3300 = 33 cM Incorrect distance =

½(3,534) + 3×(32 + 179)

9,600

1,767 + 633

9,600

2,400

9,600

= 0.2500 = 25 cM Correct MC

a844_e1a6

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene M is connected with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is associated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

288

4,194

5,355

2,610

TOTAL =

12,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and N

distance =

½(2,610 + 4,194) + 3×(63)

12,600

3,402 + 189

12,600

3,591

12,600

= 0.2850 = 28.50 cM Incorrect distance =

½(2,610) + 3×(63 + 90)

12,600

1,305 + 459

12,600

1,764

12,600

= 0.1400 = 14 cM Incorrect distance =

½(2,610 + 4,194) + 3×(90 + 288)

12,600

3,402 + 1,134

12,600

4,536

12,600

= 0.3600 = 36 cM Incorrect distance =

½(4,194) + 3×(63 + 288)

12,600

2,097 + 1,053

12,600

3,150

12,600

= 0.2500 = 25 cM Correct distance =

½(4,194) + 3×(288)

12,600

2,097 + 864

12,600

2,961

12,600

= 0.2350 = 23.50 cM Incorrect MC

897a_4983

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is correlated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene J is connected with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene P is associated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

1,860

15,122

4,488

TOTAL =

21,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and P

distance =

½(4,488) + 3×(36 + 80)

21,600

2,244 + 348

21,600

2,592

21,600

= 0.1200 = 12 cM Incorrect distance =

½(1,860 + 4,488) + 3×(14 + 36 + 80)

21,600

3,174 + 390

21,600

3,564

21,600

= 0.1650 = 16.50 cM Incorrect distance =

½(4,488) + 3×(80)

21,600

2,244 + 240

21,600

2,484

21,600

= 0.1150 = 11.50 cM Incorrect distance =

½(1,860) + 3×(14 + 36)

21,600

930 + 150

21,600

1,080

21,600

= 0.0500 = 5 cM Incorrect distance =

½(1,860 + 4,488) + 3×(14 + 80)

21,600

3,174 + 282

21,600

3,456

21,600

= 0.1600 = 16 cM Correct MC

c52b_d6f8

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is analogous to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene C is linked with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene D is associated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.

Set #

Tetrad Genotypes

Progeny
Count

2,190

173

4,290

7,632

TOTAL =

14,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and C

distance =

½(2,190) + 3×(43 + 72)

14,400

1,095 + 345

14,400

1,440

14,400

= 0.1000 = 10 cM Incorrect distance =

½(2,190 + 4,290) + 3×(43 + 173)

14,400

3,240 + 648

14,400

3,888

14,400

= 0.2700 = 27 cM Correct distance =

½(4,290) + 3×(173)

14,400

2,145 + 519

14,400

2,664

14,400

= 0.1850 = 18.50 cM Incorrect distance =

½(2,190 + 4,290) + 3×(72)

14,400

3,240 + 216

14,400

3,456

14,400

= 0.2400 = 24 cM Incorrect distance =

½(4,290) + 3×(72 + 173)

14,400

2,145 + 735

14,400

2,880

14,400

= 0.2000 = 20 cM Incorrect MC

4289_8cd5

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene T is correlated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

117

119

4,200

185

5,208

13,571

TOTAL =

23,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes T and Y

distance =

½(5,208) + 3×(117 + 185)

23,400

2,604 + 906

23,400

3,510

23,400

= 0.1500 = 15 cM Incorrect distance =

½(4,200) + 3×(117 + 119)

23,400

2,100 + 708

23,400

2,808

23,400

= 0.1200 = 12 cM Incorrect distance =

½(5,208) + 3×(185)

23,400

2,604 + 555

23,400

3,159

23,400

= 0.1350 = 13.50 cM Incorrect distance =

½(4,200 + 5,208) + 3×(117 + 119 + 185)

23,400

4,704 + 1,263

23,400

5,967

23,400

= 0.2550 = 25.50 cM Incorrect distance =

½(4,200 + 5,208) + 3×(119 + 185)

23,400

4,704 + 912

23,400

5,616

23,400

= 0.2400 = 24 cM Correct MC

90cf_5945

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is associated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene N is affiliated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene T is related to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

1,866

221

4,554

5,310

TOTAL =

12,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and T

distance =

½(4,554) + 3×(221)

12,000

2,277 + 663

12,000

2,940

12,000

= 0.2450 = 24.50 cM Incorrect distance =

½(4,554) + 3×(29)

12,000

2,277 + 87

12,000

2,364

12,000

= 0.1970 = 19.70 cM Incorrect distance =

½(4,554) + 3×(20 + 221)

12,000

2,277 + 723

12,000

3,000

12,000

= 0.2500 = 25 cM Correct distance =

½(1,866 + 4,554) + 3×(29 + 221)

12,000

3,210 + 750

12,000

3,960

12,000

= 0.3300 = 33 cM Incorrect distance =

½(1,866) + 3×(20 + 29)

12,000

933 + 147

12,000

1,080

12,000

= 0.0900 = 9 cM Incorrect MC

60a4_8eb7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.

Set #

Tetrad Genotypes

Progeny
Count

119

153

2,448

4,284

2,958

238

TOTAL =

10,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and H

distance =

½(2,448) + 3×(119 + 153 + 238)

10,200

1,224 + 1,530

10,200

2,754

10,200

= 0.2700 = 27 cM Incorrect distance =

½(2,958) + 3×(119 + 238)

10,200

1,479 + 1,071

10,200

2,550

10,200

= 0.2500 = 25 cM Correct distance =

½(2,958) + 3×(119)

10,200

1,479 + 357

10,200

1,836

10,200

= 0.1800 = 18 cM Incorrect distance =

½(2,958) + 3×(153)

10,200

1,479 + 459

10,200

1,938

10,200

= 0.1900 = 19 cM Incorrect distance =

½(2,958) + 3×(153 + 238)

10,200

1,479 + 1,173

10,200

2,652

10,200

= 0.2600 = 26 cM Incorrect MC

da8e_6003

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is affiliated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene J is analogous to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene Y is correlated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,098

8,094

12,875

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and Y

distance =

½(1,098) + 3×(2 + 37)

22,200

549 + 117

22,200

666

22,200

= 0.0300 = 3 cM Incorrect distance =

½(1,098 + 8,094) + 3×(2 + 94)

22,200

4,596 + 288

22,200

4,884

22,200

= 0.2200 = 22 cM Incorrect distance =

½(8,094) + 3×(37 + 94)

22,200

4,047 + 393

22,200

4,440

22,200

= 0.2000 = 20 cM Correct distance =

½(8,094) + 3×(94)

22,200

4,047 + 282

22,200

4,329

22,200

= 0.1950 = 19.50 cM Incorrect distance =

½(1,098) + 3×(2)

22,200

549 + 6

22,200

555

22,200

= 0.0250 = 2.50 cM Incorrect MC

ad86_fad8

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is related to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene C is connected with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene Y is analogous to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,170

2,450

1,296

TOTAL =

5,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and Y

distance =

½(1,170) + 3×(51 + 60)

5,100

585 + 333

5,100

918

5,100

= 0.1800 = 18 cM Incorrect distance =

½(1,296) + 3×(73)

5,100

648 + 219

5,100

867

5,100

= 0.1700 = 17 cM Incorrect distance =

½(1,170 + 1,296) + 3×(51 + 60 + 73)

5,100

1,233 + 552

5,100

1,785

5,100

= 0.3500 = 35 cM Incorrect distance =

½(1,170) + 3×(60)

5,100

585 + 180

5,100

765

5,100

= 0.1500 = 15 cM Incorrect distance =

½(1,170 + 1,296) + 3×(60 + 73)

5,100

1,233 + 399

5,100

1,632

5,100

= 0.3200 = 32 cM Correct MC

1580_04c9

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene P is correlated with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene T is connected with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

11,548

4,326

6,672

126

351

TOTAL =

23,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and P

distance =

½(4,326) + 3×(126)

23,100

2,163 + 378

23,100

2,541

23,100

= 0.1100 = 11 cM Incorrect distance =

½(4,326 + 6,672) + 3×(77 + 126 + 351)

23,100

5,499 + 1,662

23,100

7,161

23,100

= 0.3100 = 31 cM Incorrect distance =

½(4,326 + 6,672) + 3×(126 + 351)

23,100

5,499 + 1,431

23,100

6,930

23,100

= 0.3000 = 30 cM Correct distance =

½(6,672) + 3×(351)

23,100

3,336 + 1,053

23,100

4,389

23,100

= 0.1900 = 19 cM Incorrect distance =

½(4,326) + 3×(77 + 126)

23,100

2,163 + 609

23,100

2,772

23,100

= 0.1200 = 12 cM Incorrect MC

196b_fbaa

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is linked with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is analogous to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

212

3,858

6,550

2,646

135

TOTAL =

13,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and Y

distance =

½(2,646) + 3×(99 + 135)

13,500

1,323 + 702

13,500

2,025

13,500

= 0.1500 = 15 cM Incorrect distance =

½(2,646 + 3,858) + 3×(99 + 135 + 212)

13,500

3,252 + 1,338

13,500

4,590

13,500

= 0.3400 = 34 cM Incorrect distance =

½(2,646 + 3,858) + 3×(99 + 212)

13,500

3,252 + 933

13,500

4,185

13,500

= 0.3100 = 31 cM Incorrect distance =

½(2,646) + 3×(99)

13,500

1,323 + 297

13,500

1,620

13,500

= 0.1200 = 12 cM Incorrect distance =

½(3,858) + 3×(135 + 212)

13,500

1,929 + 1,041

13,500

2,970

13,500

= 0.2200 = 22 cM Correct MC

5f8a_7617

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene T is correlated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

3,162

16,145

3,906

TOTAL =

23,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and W

distance =

½(3,162) + 3×(58)

23,400

1,581 + 174

23,400

1,755

23,400

= 0.0750 = 7.50 cM Incorrect distance =

½(3,162) + 3×(39 + 58)

23,400

1,581 + 291

23,400

1,872

23,400

= 0.0800 = 8 cM Incorrect distance =

½(3,906) + 3×(90)

23,400

1,953 + 270

23,400

2,223

23,400

= 0.0950 = 9.50 cM Incorrect distance =

½(3,162 + 3,906) + 3×(58 + 90)

23,400

3,534 + 444

23,400

3,978

23,400

= 0.1700 = 17 cM Correct distance =

½(3,906) + 3×(39 + 90)

23,400

1,953 + 387

23,400

2,340

23,400

= 0.1000 = 10 cM Incorrect MC

8973_1d3c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is linked with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene X is analogous to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is analogous to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

2,196

13,609

12,042

249

TOTAL =

28,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and X

distance =

½(2,196) + 3×(10)

28,200

1,098 + 30

28,200

1,128

28,200

= 0.0400 = 4 cM Incorrect distance =

½(12,042) + 3×(94 + 249)

28,200

6,021 + 1,029

28,200

7,050

28,200

= 0.2500 = 25 cM Incorrect distance =

½(2,196 + 12,042) + 3×(10 + 94 + 249)

28,200

7,119 + 1,059

28,200

8,178

28,200

= 0.2900 = 29 cM Incorrect distance =

½(2,196) + 3×(10 + 94)

28,200

1,098 + 312

28,200

1,410

28,200

= 0.0500 = 5 cM Correct distance =

½(12,042) + 3×(249)

28,200

6,021 + 747

28,200

6,768

28,200

= 0.2400 = 24 cM Incorrect MC

c8c2_2661

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is correlated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

20,737

2,970

4,920

TOTAL =

28,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and Y

distance =

½(4,920) + 3×(92)

28,800

2,460 + 276

28,800

2,736

28,800

= 0.0950 = 9.50 cM Incorrect distance =

½(4,920) + 3×(48 + 92)

28,800

2,460 + 420

28,800

2,880

28,800

= 0.1000 = 10 cM Correct distance =

½(2,970) + 3×(33 + 48)

28,800

1,485 + 243

28,800

1,728

28,800

= 0.0600 = 6 cM Incorrect distance =

½(2,970) + 3×(33)

28,800

1,485 + 99

28,800

1,584

28,800

= 0.0550 = 5.50 cM Incorrect distance =

½(2,970 + 4,920) + 3×(33 + 92)

28,800

3,945 + 375

28,800

4,320

28,800

= 0.1500 = 15 cM Incorrect MC

760c_1198

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene W is correlated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene Y is linked with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

379

4,614

293

4,122

7,140

252

TOTAL =

16,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and Y

distance =

½(4,122 + 4,614) + 3×(293 + 379)

16,800

4,368 + 2,016

16,800

6,384

16,800

= 0.3800 = 38 cM Incorrect distance =

½(4,614) + 3×(252 + 379)

16,800

2,307 + 1,893

16,800

4,200

16,800

= 0.2500 = 25 cM Incorrect distance =

½(4,122) + 3×(293)

16,800

2,061 + 879

16,800

2,940

16,800

= 0.1750 = 17.50 cM Incorrect distance =

½(4,122) + 3×(252 + 293)

16,800

2,061 + 1,635

16,800

3,696

16,800

= 0.2200 = 22 cM Correct distance =

½(4,122 + 4,614) + 3×(252 + 293 + 379)

16,800

4,368 + 2,772

16,800

7,140

16,800

= 0.4250 = 42.50 cM Incorrect MC

5986_78b9

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is associated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is analogous to the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene M is associated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

3,000

126

223

5,466

10,018

TOTAL =

18,900

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and M

distance =

½(3,000 + 5,466) + 3×(67 + 223)

18,900

4,233 + 870

18,900

5,103

18,900

= 0.2700 = 27 cM Incorrect distance =

½(3,000) + 3×(67)

18,900

1,500 + 201

18,900

1,701

18,900

= 0.0900 = 9 cM Incorrect distance =

½(5,466) + 3×(223)

18,900

2,733 + 669

18,900

3,402

18,900

= 0.1800 = 18 cM Incorrect distance =

½(5,466) + 3×(126 + 223)

18,900

2,733 + 1,047

18,900

3,780

18,900

= 0.2000 = 20 cM Correct distance =

½(3,000 + 5,466) + 3×(67 + 126 + 223)

18,900

4,233 + 1,248

18,900

5,481

18,900

= 0.2900 = 29 cM Incorrect MC

996c_c6c8

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is linked with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene D is linked with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene H is analogous to the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.

Set #

Tetrad Genotypes

Progeny
Count

212

8,874

2,556

14,950

TOTAL =

26,700

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and H

distance =

½(2,556) + 3×(19)

26,700

1,278 + 57

26,700

1,335

26,700

= 0.0500 = 5 cM Incorrect distance =

½(8,874) + 3×(89 + 212)

26,700

4,437 + 903

26,700

5,340

26,700

= 0.2000 = 20 cM Incorrect distance =

½(2,556) + 3×(19 + 89)

26,700

1,278 + 324

26,700

1,602

26,700

= 0.0600 = 6 cM Correct distance =

½(8,874) + 3×(212)

26,700

4,437 + 636

26,700

5,073

26,700

= 0.1900 = 19 cM Incorrect distance =

½(2,556 + 8,874) + 3×(19 + 212)

26,700

5,715 + 693

26,700

6,408

26,700

= 0.2400 = 24 cM Incorrect MC

4ce5_c4c4

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene J is linked with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene T is analogous to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

116

2,262

119

4,437

3,042

224

TOTAL =

10,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and T

distance =

½(2,262 + 3,042) + 3×(116 + 224)

10,200

2,652 + 1,020

10,200

3,672

10,200

= 0.3600 = 36 cM Correct distance =

½(2,262 + 3,042) + 3×(119)

10,200

2,652 + 357

10,200

3,009

10,200

= 0.2950 = 29.50 cM Incorrect distance =

½(2,262) + 3×(116 + 119)

10,200

1,131 + 705

10,200

1,836

10,200

= 0.1800 = 18 cM Incorrect distance =

½(2,262) + 3×(116)

10,200

1,131 + 348

10,200

1,479

10,200

= 0.1450 = 14.50 cM Incorrect distance =

½(3,042) + 3×(119 + 224)

10,200

1,521 + 1,029

10,200

2,550

10,200

= 0.2500 = 25 cM Incorrect MC

797b_a3bb

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene X is related to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

229

5,592

129

11,737

7,620

493

TOTAL =

25,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and X

distance =

½(5,592 + 7,620) + 3×(129 + 229 + 493)

25,800

6,606 + 2,553

25,800

9,159

25,800

= 0.3550 = 35.50 cM Incorrect distance =

½(5,592) + 3×(129 + 229)

25,800

2,796 + 1,074

25,800

3,870

25,800

= 0.1500 = 15 cM Incorrect distance =

½(5,592 + 7,620) + 3×(229 + 493)

25,800

6,606 + 2,166

25,800

8,772

25,800

= 0.3400 = 34 cM Incorrect distance =

½(5,592) + 3×(229)

25,800

2,796 + 687

25,800

3,483

25,800

= 0.1350 = 13.50 cM Incorrect distance =

½(7,620) + 3×(129 + 493)

25,800

3,810 + 1,866

25,800

5,676

25,800

= 0.2200 = 22 cM Correct MC

4ba5_30d7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene F is associated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

238

5,982

10,335

2,832

TOTAL =

19,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and F

distance =

½(2,832) + 3×(48 + 65)

19,500

1,416 + 339

19,500

1,755

19,500

= 0.0900 = 9 cM Correct distance =

½(2,832 + 5,982) + 3×(48 + 238)

19,500

4,407 + 858

19,500

5,265

19,500

= 0.2700 = 27 cM Incorrect distance =

½(5,982) + 3×(238)

19,500

2,991 + 714

19,500

3,705

19,500

= 0.1900 = 19 cM Incorrect distance =

½(5,982) + 3×(65 + 238)

19,500

2,991 + 909

19,500

3,900

19,500

= 0.2000 = 20 cM Incorrect distance =

½(2,832) + 3×(48)

19,500

1,416 + 144

19,500

1,560

19,500

= 0.0800 = 8 cM Incorrect MC

53ae_0536

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is affiliated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene J is connected with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene N is analogous to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

299

7,626

12,010

3,396

157

TOTAL =

23,550

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and J

distance =

½(3,396 + 7,626) + 3×(62 + 157 + 299)

23,550

5,511 + 1,554

23,550

7,065

23,550

= 0.3000 = 30 cM Incorrect distance =

½(7,626) + 3×(157 + 299)

23,550

3,813 + 1,368

23,550

5,181

23,550

= 0.2200 = 22 cM Incorrect distance =

½(7,626) + 3×(299)

23,550

3,813 + 897

23,550

4,710

23,550

= 0.2000 = 20 cM Incorrect distance =

½(3,396) + 3×(62 + 157)

23,550

1,698 + 657

23,550

2,355

23,550

= 0.1000 = 10 cM Correct distance =

½(3,396 + 7,626) + 3×(62 + 299)

23,550

5,511 + 1,083

23,550

6,594

23,550

= 0.2800 = 28 cM Incorrect MC

d127_30fc

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is correlated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene F is analogous to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene T is correlated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

163

2,622

1,428

3,225

TOTAL =

7,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and T

distance =

½(1,428 + 2,622) + 3×(25)

7,500

2,025 + 75

7,500

2,100

7,500

= 0.2800 = 28 cM Incorrect distance =

½(1,428) + 3×(25 + 37)

7,500

714 + 186

7,500

900

7,500

= 0.1200 = 12 cM Correct distance =

½(2,622) + 3×(25 + 163)

7,500

1,311 + 564

7,500

1,875

7,500

= 0.2500 = 25 cM Incorrect distance =

½(1,428 + 2,622) + 3×(37 + 163)

7,500

2,025 + 600

7,500

2,625

7,500

= 0.3500 = 35 cM Incorrect distance =

½(2,622) + 3×(163)

7,500

1,311 + 489

7,500

1,800

7,500

= 0.2400 = 24 cM Incorrect MC

f7cc_707a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is connected with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,866

6,194

4,530

191

TOTAL =

12,900

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and W

distance =

½(4,530) + 3×(86 + 191)

12,900

2,265 + 831

12,900

3,096

12,900

= 0.2400 = 24 cM Incorrect distance =

½(1,866 + 4,530) + 3×(33 + 86 + 191)

12,900

3,198 + 930

12,900

4,128

12,900

= 0.3200 = 32 cM Incorrect distance =

½(1,866) + 3×(33)

12,900

933 + 99

12,900

1,032

12,900

= 0.0800 = 8 cM Incorrect distance =

½(4,530) + 3×(191)

12,900

2,265 + 573

12,900

2,838

12,900

= 0.2200 = 22 cM Incorrect distance =

½(1,866 + 4,530) + 3×(33 + 191)

12,900

3,198 + 672

12,900

3,870

12,900

= 0.3000 = 30 cM Correct MC

5a93_8902

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is analogous to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene T is analogous to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is affiliated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

105

5,364

14,761

1,920

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes T and W

distance =

½(1,920 + 5,364) + 3×(13 + 37 + 105)

22,200

3,642 + 465

22,200

4,107

22,200

= 0.1850 = 18.50 cM Incorrect distance =

½(1,920) + 3×(13 + 37)

22,200

960 + 150

22,200

1,110

22,200

= 0.0500 = 5 cM Incorrect distance =

½(1,920) + 3×(13)

22,200

960 + 39

22,200

999

22,200

= 0.0450 = 4.50 cM Incorrect distance =

½(5,364) + 3×(37 + 105)

22,200

2,682 + 426

22,200

3,108

22,200

= 0.1400 = 14 cM Incorrect distance =

½(1,920 + 5,364) + 3×(13 + 105)

22,200

3,642 + 354

22,200

3,996

22,200

= 0.1800 = 18 cM Correct MC

baad_7fc6

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is affiliated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene T is affiliated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

9,827

2,568

3,018

TOTAL =

15,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and T

distance =

½(2,568 + 3,018) + 3×(26 + 66 + 95)

15,600

2,793 + 561

15,600

3,354

15,600

= 0.2150 = 21.50 cM Incorrect distance =

½(2,568) + 3×(26 + 66)

15,600

1,284 + 276

15,600

1,560

15,600

= 0.1000 = 10 cM Incorrect distance =

½(3,018) + 3×(26 + 95)

15,600

1,509 + 363

15,600

1,872

15,600

= 0.1200 = 12 cM Incorrect distance =

½(2,568 + 3,018) + 3×(66 + 95)

15,600

2,793 + 483

15,600

3,276

15,600

= 0.2100 = 21 cM Correct distance =

½(3,018) + 3×(95)

15,600

1,509 + 285

15,600

1,794

15,600

= 0.1150 = 11.50 cM Incorrect MC

ba6a_92d4

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is connected with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene T is connected with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

184

251

3,462

5,727

3,852

324

TOTAL =

13,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and T

distance =

½(3,852) + 3×(184 + 324)

13,800

1,926 + 1,524

13,800

3,450

13,800

= 0.2500 = 25 cM Incorrect distance =

½(3,462) + 3×(251)

13,800

1,731 + 753

13,800

2,484

13,800

= 0.1800 = 18 cM Incorrect distance =

½(3,462 + 3,852) + 3×(251 + 324)

13,800

3,657 + 1,725

13,800

5,382

13,800

= 0.3900 = 39 cM Correct distance =

½(3,852) + 3×(324)

13,800

1,926 + 972

13,800

2,898

13,800

= 0.2100 = 21 cM Incorrect distance =

½(3,462 + 3,852) + 3×(184 + 251 + 324)

13,800

3,657 + 2,277

13,800

5,934

13,800

= 0.4300 = 43 cM Incorrect MC

1ded_7f13

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is affiliated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene F is related to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,578

1,446

2,760

TOTAL =

6,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and F

distance =

½(1,578) + 3×(97)

6,000

789 + 291

6,000

1,080

6,000

= 0.1800 = 18 cM Incorrect distance =

½(1,446 + 1,578) + 3×(79 + 97)

6,000

1,512 + 528

6,000

2,040

6,000

= 0.3400 = 34 cM Correct distance =

½(1,578) + 3×(40 + 97)

6,000

789 + 411

6,000

1,200

6,000

= 0.2000 = 20 cM Incorrect distance =

½(1,446 + 1,578) + 3×(40 + 79 + 97)

6,000

1,512 + 648

6,000

2,160

6,000

= 0.3600 = 36 cM Incorrect distance =

½(1,446) + 3×(79)

6,000

723 + 237

6,000

960

6,000

= 0.1600 = 16 cM Incorrect MC

93d2_441b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is affiliated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene E is linked with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.

Set #

Tetrad Genotypes

Progeny
Count

112

3,000

153

7,039

4,710

286

TOTAL =

15,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and F

distance =

½(3,000 + 4,710) + 3×(112 + 153 + 286)

15,300

3,855 + 1,653

15,300

5,508

15,300

= 0.3600 = 36 cM Incorrect distance =

½(4,710) + 3×(286)

15,300

2,355 + 858

15,300

3,213

15,300

= 0.2100 = 21 cM Incorrect distance =

½(3,000 + 4,710) + 3×(112 + 286)

15,300

3,855 + 1,194

15,300

5,049

15,300

= 0.3300 = 33 cM Incorrect distance =

½(4,710) + 3×(153 + 286)

15,300

2,355 + 1,317

15,300

3,672

15,300

= 0.2400 = 24 cM Correct distance =

½(3,000) + 3×(112 + 153)

15,300

1,500 + 795

15,300

2,295

15,300

= 0.1500 = 15 cM Incorrect MC

16d0_3364

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is affiliated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene P is related to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene T is connected with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

2,394

259

3,966

5,220

TOTAL =

12,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and T

distance =

½(2,394 + 3,966) + 3×(80 + 81 + 259)

12,000

3,180 + 1,260

12,000

4,440

12,000

= 0.3700 = 37 cM Incorrect distance =

½(3,966) + 3×(80 + 259)

12,000

1,983 + 1,017

12,000

3,000

12,000

= 0.2500 = 25 cM Correct distance =

½(2,394) + 3×(80 + 81)

12,000

1,197 + 483

12,000

1,680

12,000

= 0.1400 = 14 cM Incorrect distance =

½(2,394) + 3×(81)

12,000

1,197 + 243

12,000

1,440

12,000

= 0.1200 = 12 cM Incorrect distance =

½(2,394 + 3,966) + 3×(81 + 259)

12,000

3,180 + 1,020

12,000

4,200

12,000

= 0.3500 = 35 cM Incorrect MC

83fa_af01

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is associated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,716

12,472

5,454

114

TOTAL =

19,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and P

distance =

½(1,716 + 5,454) + 3×(11 + 114)

19,800

3,585 + 375

19,800

3,960

19,800

= 0.2000 = 20 cM Incorrect distance =

½(1,716) + 3×(11 + 33)

19,800

858 + 132

19,800

990

19,800

= 0.0500 = 5 cM Correct distance =

½(5,454) + 3×(33 + 114)

19,800

2,727 + 441

19,800

3,168

19,800

= 0.1600 = 16 cM Incorrect distance =

½(1,716) + 3×(11)

19,800

858 + 33

19,800

891

19,800

= 0.0450 = 4.50 cM Incorrect distance =

½(5,454) + 3×(114)

19,800

2,727 + 342

19,800

3,069

19,800

= 0.1550 = 15.50 cM Incorrect MC

9513_4a5f

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is connected with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene N is affiliated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene Y is associated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

2,796

882

4,621

TOTAL =

8,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and Y

distance =

½(882) + 3×(7 + 14)

8,400

441 + 63

8,400

504

8,400

= 0.0600 = 6 cM Incorrect distance =

½(882 + 2,796) + 3×(7 + 80)

8,400

1,839 + 261

8,400

2,100

8,400

= 0.2500 = 25 cM Incorrect distance =

½(2,796) + 3×(14 + 80)

8,400

1,398 + 282

8,400

1,680

8,400

= 0.2000 = 20 cM Correct distance =

½(2,796) + 3×(80)

8,400

1,398 + 240

8,400

1,638

8,400

= 0.1950 = 19.50 cM Incorrect distance =

½(882 + 2,796) + 3×(7 + 14 + 80)

8,400

1,839 + 303

8,400

2,142

8,400

= 0.2550 = 25.50 cM Incorrect MC

991b_c8e7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is related to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene H is correlated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene W is affiliated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

2,616

5,544

4,644

304

TOTAL =

13,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and W

distance =

½(2,616 + 4,644) + 3×(70 + 304)

13,200

3,630 + 1,122

13,200

4,752

13,200

= 0.3600 = 36 cM Correct distance =

½(2,616 + 4,644) + 3×(22 + 70 + 304)

13,200

3,630 + 1,188

13,200

4,818

13,200

= 0.3650 = 36.50 cM Incorrect distance =

½(4,644) + 3×(22 + 304)

13,200

2,322 + 978

13,200

3,300

13,200

= 0.2500 = 25 cM Incorrect distance =

½(2,616) + 3×(22 + 70)

13,200

1,308 + 276

13,200

1,584

13,200

= 0.1200 = 12 cM Incorrect distance =

½(2,616 + 4,644) + 3×(22)

13,200

3,630 + 66

13,200

3,696

13,200

= 0.2800 = 28 cM Incorrect MC

ab55_5fac

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is linked with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene M is connected with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

486

10,338

12,831

4,326

141

TOTAL =

28,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and M

distance =

½(10,338) + 3×(486)

28,200

5,169 + 1,458

28,200

6,627

28,200

= 0.2350 = 23.50 cM Incorrect distance =

½(4,326 + 10,338) + 3×(78 + 486)

28,200

7,332 + 1,692

28,200

9,024

28,200

= 0.3200 = 32 cM Correct distance =

½(4,326) + 3×(78)

28,200

2,163 + 234

28,200

2,397

28,200

= 0.0850 = 8.50 cM Incorrect distance =

½(10,338) + 3×(141 + 486)

28,200

5,169 + 1,881

28,200

7,050

28,200

= 0.2500 = 25 cM Incorrect distance =

½(4,326) + 3×(78 + 141)

28,200

2,163 + 657

28,200

2,820

28,200

= 0.1000 = 10 cM Incorrect MC

6139_8e98

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is related to the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene J is linked with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene N is linked with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

4,048

1,518

2,340

123

TOTAL =

8,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and J

distance =

½(1,518 + 2,340) + 3×(44 + 123)

8,100

1,929 + 501

8,100

2,430

8,100

= 0.3000 = 30 cM Correct distance =

½(2,340) + 3×(27 + 123)

8,100

1,170 + 450

8,100

1,620

8,100

= 0.2000 = 20 cM Incorrect distance =

½(1,518) + 3×(44)

8,100

759 + 132

8,100

891

8,100

= 0.1100 = 11 cM Incorrect distance =

½(1,518 + 2,340) + 3×(27 + 44 + 123)

8,100

1,929 + 582

8,100

2,511

8,100

= 0.3100 = 31 cM Incorrect distance =

½(2,340) + 3×(123)

8,100

1,170 + 369

8,100

1,539

8,100

= 0.1900 = 19 cM Incorrect MC

25e5_40bf

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is connected with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,044

114

2,076

2,700

TOTAL =

6,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and H

distance =

½(2,076) + 3×(40 + 114)

6,000

1,038 + 462

6,000

1,500

6,000

= 0.2500 = 25 cM Incorrect distance =

½(2,076) + 3×(114)

6,000

1,038 + 342

6,000

1,380

6,000

= 0.2300 = 23 cM Incorrect distance =

½(1,044) + 3×(26)

6,000

522 + 78

6,000

600

6,000

= 0.1000 = 10 cM Incorrect distance =

½(1,044 + 2,076) + 3×(40)

6,000

1,560 + 120

6,000

1,680

6,000

= 0.2800 = 28 cM Incorrect distance =

½(1,044 + 2,076) + 3×(26 + 114)

6,000

1,560 + 420

6,000

1,980

6,000

= 0.3300 = 33 cM Correct MC

587d_1409

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is analogous to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene N is associated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene W is analogous to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

834

1,476

1,764

TOTAL =

4,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and W

distance =

½(834 + 1,476) + 3×(7)

4,200

1,155 + 21

4,200

1,176

4,200

= 0.2800 = 28 cM Incorrect distance =

½(1,476) + 3×(97)

4,200

738 + 291

4,200

1,029

4,200

= 0.2450 = 24.50 cM Incorrect distance =

½(834) + 3×(7 + 22)

4,200

417 + 87

4,200

504

4,200

= 0.1200 = 12 cM Correct distance =

½(1,476) + 3×(7 + 97)

4,200

738 + 312

4,200

1,050

4,200

= 0.2500 = 25 cM Incorrect distance =

½(834 + 1,476) + 3×(22 + 97)

4,200

1,155 + 357

4,200

1,512

4,200

= 0.3600 = 36 cM Incorrect MC

71a4_783b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene K is affiliated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene Y is analogous to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

110

2,742

281

3,984

5,420

TOTAL =

12,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and K

distance =

½(2,742 + 3,984) + 3×(63 + 110 + 281)

12,600

3,363 + 1,362

12,600

4,725

12,600

= 0.3750 = 37.50 cM Incorrect distance =

½(2,742) + 3×(63 + 110)

12,600

1,371 + 519

12,600

1,890

12,600

= 0.1500 = 15 cM Correct distance =

½(3,984) + 3×(63 + 281)

12,600

1,992 + 1,032

12,600

3,024

12,600

= 0.2400 = 24 cM Incorrect distance =

½(2,742 + 3,984) + 3×(110 + 281)

12,600

3,363 + 1,173

12,600

4,536

12,600

= 0.3600 = 36 cM Incorrect distance =

½(3,984) + 3×(281)

12,600

1,992 + 843

12,600

2,835

12,600

= 0.2250 = 22.50 cM Incorrect MC

86ed_13d7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene T is analogous to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

111

2,844

5,940

4,230

285

TOTAL =

13,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and T

distance =

½(2,844 + 4,230) + 3×(90 + 111 + 285)

13,500

3,537 + 1,458

13,500

4,995

13,500

= 0.3700 = 37 cM Incorrect distance =

½(4,230) + 3×(90 + 285)

13,500

2,115 + 1,125

13,500

3,240

13,500

= 0.2400 = 24 cM Correct distance =

½(2,844 + 4,230) + 3×(111 + 285)

13,500

3,537 + 1,188

13,500

4,725

13,500

= 0.3500 = 35 cM Incorrect distance =

½(4,230) + 3×(285)

13,500

2,115 + 855

13,500

2,970

13,500

= 0.2200 = 22 cM Incorrect distance =

½(2,844) + 3×(90 + 111)

13,500

1,422 + 603

13,500

2,025

13,500

= 0.1500 = 15 cM Incorrect MC

02ad_946e

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is associated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene Y is affiliated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

204

5,472

438

7,974

279

13,533

TOTAL =

27,900

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and M

distance =

½(5,472 + 7,974) + 3×(204 + 438)

27,900

6,723 + 1,926

27,900

8,649

27,900

= 0.3100 = 31 cM Correct distance =

½(5,472 + 7,974) + 3×(204 + 279 + 438)

27,900

6,723 + 2,763

27,900

9,486

27,900

= 0.3400 = 34 cM Incorrect distance =

½(7,974) + 3×(438)

27,900

3,987 + 1,314

27,900

5,301

27,900

= 0.1900 = 19 cM Incorrect distance =

½(5,472) + 3×(204)

27,900

2,736 + 612

27,900

3,348

27,900

= 0.1200 = 12 cM Incorrect distance =

½(5,472) + 3×(204 + 279)

27,900

2,736 + 1,449

27,900

4,185

27,900

= 0.1500 = 15 cM Incorrect MC

a2a6_929c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is affiliated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene M is analogous to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

3,282

148

4,458

11,733

TOTAL =

19,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and H

distance =

½(3,282) + 3×(80 + 99)

19,800

1,641 + 537

19,800

2,178

19,800

= 0.1100 = 11 cM Incorrect distance =

½(3,282 + 4,458) + 3×(80 + 148)

19,800

3,870 + 684

19,800

4,554

19,800

= 0.2300 = 23 cM Correct distance =

½(3,282) + 3×(80)

19,800

1,641 + 240

19,800

1,881

19,800

= 0.0950 = 9.50 cM Incorrect distance =

½(4,458) + 3×(99 + 148)

19,800

2,229 + 741

19,800

2,970

19,800

= 0.1500 = 15 cM Incorrect distance =

½(4,458) + 3×(148)

19,800

2,229 + 444

19,800

2,673

19,800

= 0.1350 = 13.50 cM Incorrect MC

c385_22b1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

132

134

3,948

427

6,546

8,613

TOTAL =

19,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and R

distance =

½(6,546) + 3×(427)

19,800

3,273 + 1,281

19,800

4,554

19,800

= 0.2300 = 23 cM Incorrect distance =

½(3,948) + 3×(132 + 134)

19,800

1,974 + 798

19,800

2,772

19,800

= 0.1400 = 14 cM Incorrect distance =

½(6,546) + 3×(132 + 427)

19,800

3,273 + 1,677

19,800

4,950

19,800

= 0.2500 = 25 cM Correct distance =

½(3,948 + 6,546) + 3×(134 + 427)

19,800

5,247 + 1,683

19,800

6,930

19,800

= 0.3500 = 35 cM Incorrect distance =

½(3,948 + 6,546) + 3×(132 + 134 + 427)

19,800

5,247 + 2,079

19,800

7,326

19,800

= 0.3700 = 37 cM Incorrect MC

0e46_15bb

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is associated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene P is linked with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene Y is linked with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,962

12,159

10,764

222

TOTAL =

25,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and Y

distance =

½(1,962) + 3×(9)

25,200

981 + 27

25,200

1,008

25,200

= 0.0400 = 4 cM Incorrect distance =

½(1,962) + 3×(9 + 84)

25,200

981 + 279

25,200

1,260

25,200

= 0.0500 = 5 cM Incorrect distance =

½(1,962 + 10,764) + 3×(9 + 222)

25,200

6,363 + 693

25,200

7,056

25,200

= 0.2800 = 28 cM Incorrect distance =

½(10,764) + 3×(222)

25,200

5,382 + 666

25,200

6,048

25,200

= 0.2400 = 24 cM Incorrect distance =

½(10,764) + 3×(84 + 222)

25,200

5,382 + 918

25,200

6,300

25,200

= 0.2500 = 25 cM Correct MC

7bdf_9acb

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is connected with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene X is associated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

1,242

318

1,395

TOTAL =

3,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and X

distance =

½(318) + 3×(2 + 5)

3,000

159 + 21

3,000

180

3,000

= 0.0600 = 6 cM Incorrect distance =

½(318 + 1,242) + 3×(5)

3,000

780 + 15

3,000

795

3,000

= 0.2650 = 26.50 cM Incorrect distance =

½(1,242) + 3×(2 + 5)

3,000

621 + 21

3,000

642

3,000

= 0.2140 = 21.40 cM Incorrect distance =

½(1,242) + 3×(5 + 38)

3,000

621 + 129

3,000

750

3,000

= 0.2500 = 25 cM Correct distance =

½(318 + 1,242) + 3×(2 + 38)

3,000

780 + 120

3,000

900

3,000

= 0.3000 = 30 cM Incorrect MC

a8ea_3712

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is linked with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene N is associated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

822

2,004

2,737

TOTAL =

5,700

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and N

distance =

½(822) + 3×(15 + 38)

5,700

411 + 159

5,700

570

5,700

= 0.1000 = 10 cM Incorrect distance =

½(822 + 2,004) + 3×(15 + 84)

5,700

1,413 + 297

5,700

1,710

5,700

= 0.3000 = 30 cM Incorrect distance =

½(2,004) + 3×(38 + 84)

5,700

1,002 + 366

5,700

1,368

5,700

= 0.2400 = 24 cM Correct distance =

½(822) + 3×(15)

5,700

411 + 45

5,700

456

5,700

= 0.0800 = 8 cM Incorrect distance =

½(2,004) + 3×(84)

5,700

1,002 + 252

5,700

1,254

5,700

= 0.2200 = 22 cM Incorrect MC

770e_7009

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene E is related to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.

Set #

Tetrad Genotypes

Progeny
Count

102

178

4,440

454

6,456

8,770

TOTAL =

20,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and C

distance =

½(4,440 + 6,456) + 3×(178 + 454)

20,400

5,448 + 1,896

20,400

7,344

20,400

= 0.3600 = 36 cM Incorrect distance =

½(6,456) + 3×(454)

20,400

3,228 + 1,362

20,400

4,590

20,400

= 0.2250 = 22.50 cM Incorrect distance =

½(4,440) + 3×(178)

20,400

2,220 + 534

20,400

2,754

20,400

= 0.1350 = 13.50 cM Incorrect distance =

½(4,440) + 3×(102 + 178)

20,400

2,220 + 840

20,400

3,060

20,400

= 0.1500 = 15 cM Correct distance =

½(6,456) + 3×(102 + 454)

20,400

3,228 + 1,668

20,400

4,896

20,400

= 0.2400 = 24 cM Incorrect MC

1e73_883c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is correlated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene D is correlated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene J is linked with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.

Set #

Tetrad Genotypes

Progeny
Count

426

1,038

1,783

TOTAL =

3,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and D

distance =

½(426 + 1,038) + 3×(6 + 11 + 36)

3,300

732 + 159

3,300

891

3,300

= 0.2700 = 27 cM Incorrect distance =

½(426 + 1,038) + 3×(6 + 36)

3,300

732 + 126

3,300

858

3,300

= 0.2600 = 26 cM Correct distance =

½(426) + 3×(6 + 11)

3,300

213 + 51

3,300

264

3,300

= 0.0800 = 8 cM Incorrect distance =

½(1,038) + 3×(36)

3,300

519 + 108

3,300

627

3,300

= 0.1900 = 19 cM Incorrect distance =

½(426) + 3×(6)

3,300

213 + 18

3,300

231

3,300

= 0.0700 = 7 cM Incorrect MC

fa23_f7e0

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene T is affiliated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene Y is connected with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

230

3,948

130

3,108

6,912

TOTAL =

14,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes T and Y

distance =

½(3,108 + 3,948) + 3×(72 + 130 + 230)

14,400

3,528 + 1,296

14,400

4,824

14,400

= 0.3350 = 33.50 cM Incorrect distance =

½(3,108 + 3,948) + 3×(130 + 230)

14,400

3,528 + 1,080

14,400

4,608

14,400

= 0.3200 = 32 cM Incorrect distance =

½(3,108) + 3×(72 + 130)

14,400

1,554 + 606

14,400

2,160

14,400

= 0.1500 = 15 cM Correct distance =

½(3,948) + 3×(72 + 230)

14,400

1,974 + 906

14,400

2,880

14,400

= 0.2000 = 20 cM Incorrect distance =

½(3,108 + 3,948) + 3×(72)

14,400

3,528 + 216

14,400

3,744

14,400

= 0.2600 = 26 cM Incorrect MC

6e63_585e

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene M is correlated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene N is connected with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

188

4,584

9,238

2,676

TOTAL =

16,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes M and N

distance =

½(2,676 + 4,584) + 3×(58 + 188)

16,800

3,630 + 738

16,800

4,368

16,800

= 0.2600 = 26 cM Correct distance =

½(2,676) + 3×(56 + 58)

16,800

1,338 + 342

16,800

1,680

16,800

= 0.1000 = 10 cM Incorrect distance =

½(2,676 + 4,584) + 3×(56 + 58 + 188)

16,800

3,630 + 906

16,800

4,536

16,800

= 0.2700 = 27 cM Incorrect distance =

½(2,676) + 3×(58)

16,800

1,338 + 174

16,800

1,512

16,800

= 0.0900 = 9 cM Incorrect distance =

½(4,584) + 3×(188)

16,800

2,292 + 564

16,800

2,856

16,800

= 0.1700 = 17 cM Incorrect MC

3a97_7b65

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is correlated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

197

4,380

8,035

2,664

103

TOTAL =

15,450

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and M

distance =

½(2,664) + 3×(71 + 103)

15,450

1,332 + 522

15,450

1,854

15,450

= 0.1200 = 12 cM Incorrect distance =

½(2,664 + 4,380) + 3×(71 + 103 + 197)

15,450

3,522 + 1,113

15,450

4,635

15,450

= 0.3000 = 30 cM Incorrect distance =

½(4,380) + 3×(197)

15,450

2,190 + 591

15,450

2,781

15,450

= 0.1800 = 18 cM Incorrect distance =

½(2,664 + 4,380) + 3×(71 + 197)

15,450

3,522 + 804

15,450

4,326

15,450

= 0.2800 = 28 cM Correct distance =

½(2,664) + 3×(71)

15,450

1,332 + 213

15,450

1,545

15,450

= 0.1000 = 10 cM Incorrect MC

c47e_65cd

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is linked with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene N is analogous to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

500

6,102

9,435

5,442

333

388

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and K

distance =

½(5,442 + 6,102) + 3×(388 + 500)

22,200

5,772 + 2,664

22,200

8,436

22,200

= 0.3800 = 38 cM Incorrect distance =

½(6,102) + 3×(333 + 500)

22,200

3,051 + 2,499

22,200

5,550

22,200

= 0.2500 = 25 cM Incorrect distance =

½(5,442) + 3×(388)

22,200

2,721 + 1,164

22,200

3,885

22,200

= 0.1750 = 17.50 cM Incorrect distance =

½(5,442) + 3×(333 + 388)

22,200

2,721 + 2,163

22,200

4,884

22,200

= 0.2200 = 22 cM Correct distance =

½(5,442 + 6,102) + 3×(333)

22,200

5,772 + 999

22,200

6,771

22,200

= 0.3050 = 30.50 cM Incorrect MC

569b_d9d3

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is related to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene N is connected with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

100

4,104

840

4,536

TOTAL =

9,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and N

distance =

½(840 + 4,104) + 3×(4 + 100)

9,600

2,472 + 312

9,600

2,784

9,600

= 0.2900 = 29 cM Incorrect distance =

½(840) + 3×(16 + 100)

9,600

420 + 348

9,600

768

9,600

= 0.0800 = 8 cM Incorrect distance =

½(4,104) + 3×(4 + 16)

9,600

2,052 + 60

9,600

2,112

9,600

= 0.2200 = 22 cM Incorrect distance =

½(840) + 3×(4 + 16)

9,600

420 + 60

9,600

480

9,600

= 0.0500 = 5 cM Correct distance =

½(4,104) + 3×(16 + 100)

9,600

2,052 + 348

9,600

2,400

9,600

= 0.2500 = 25 cM Incorrect MC

e3f5_f1e0

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene E is analogous to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene W is linked with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

500

7,764

12,696

6,312

282

TOTAL =

27,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and W

distance =

½(7,764) + 3×(46 + 500)

27,600

3,882 + 1,638

27,600

5,520

27,600

= 0.2000 = 20 cM Correct distance =

½(6,312 + 7,764) + 3×(282 + 500)

27,600

7,038 + 2,346

27,600

9,384

27,600

= 0.3400 = 34 cM Incorrect distance =

½(6,312 + 7,764) + 3×(46)

27,600

7,038 + 138

27,600

7,176

27,600

= 0.2600 = 26 cM Incorrect distance =

½(7,764) + 3×(500)

27,600

3,882 + 1,500

27,600

5,382

27,600

= 0.1950 = 19.50 cM Incorrect distance =

½(6,312) + 3×(46 + 282)

27,600

3,156 + 984

27,600

4,140

27,600

= 0.1500 = 15 cM Incorrect MC

b294_865a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is associated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene H is related to the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene R is related to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

117

5,736

1,920

14,377

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and H

distance =

½(1,920 + 5,736) + 3×(13 + 117)

22,200

3,828 + 390

22,200

4,218

22,200

= 0.1900 = 19 cM Correct distance =

½(5,736) + 3×(37 + 117)

22,200

2,868 + 462

22,200

3,330

22,200

= 0.1500 = 15 cM Incorrect distance =

½(5,736) + 3×(117)

22,200

2,868 + 351

22,200

3,219

22,200

= 0.1450 = 14.50 cM Incorrect distance =

½(1,920) + 3×(13 + 37)

22,200

960 + 150

22,200

1,110

22,200

= 0.0500 = 5 cM Incorrect distance =

½(1,920 + 5,736) + 3×(13 + 37 + 117)

22,200

3,828 + 501

22,200

4,329

22,200

= 0.1950 = 19.50 cM Incorrect MC

05fe_4579

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is linked with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene B is connected with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene X is associated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

2,082

109

3,882

10,042

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and X

distance =

½(3,882) + 3×(109)

16,200

1,941 + 327

16,200

2,268

16,200

= 0.1400 = 14 cM Incorrect distance =

½(3,882) + 3×(54 + 109)

16,200

1,941 + 489

16,200

2,430

16,200

= 0.1500 = 15 cM Correct distance =

½(2,082 + 3,882) + 3×(31 + 54 + 109)

16,200

2,982 + 582

16,200

3,564

16,200

= 0.2200 = 22 cM Incorrect distance =

½(2,082) + 3×(31 + 54)

16,200

1,041 + 255

16,200

1,296

16,200

= 0.0800 = 8 cM Incorrect distance =

½(2,082) + 3×(31)

16,200

1,041 + 93

16,200

1,134

16,200

= 0.0700 = 7 cM Incorrect MC

9ea3_c4d1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene J is analogous to the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.

Set #

Tetrad Genotypes

Progeny
Count

888

5,354

3,846

TOTAL =

10,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and J

distance =

½(3,846) + 3×(5)

10,200

1,923 + 15

10,200

1,938

10,200

= 0.1900 = 19 cM Incorrect distance =

½(888) + 3×(90)

10,200

444 + 270

10,200

714

10,200

= 0.0700 = 7 cM Incorrect distance =

½(888) + 3×(5 + 17)

10,200

444 + 66

10,200

510

10,200

= 0.0500 = 5 cM Correct distance =

½(888 + 3,846) + 3×(5 + 90)

10,200

2,367 + 285

10,200

2,652

10,200

= 0.2600 = 26 cM Incorrect distance =

½(3,846) + 3×(17 + 90)

10,200

1,923 + 321

10,200

2,244

10,200

= 0.2200 = 22 cM Incorrect MC

7399_4fac

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene M is connected with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene R is associated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

6,838

2,130

5,364

233

TOTAL =

14,700

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and M

distance =

½(2,130 + 5,364) + 3×(37 + 233)

14,700

3,747 + 810

14,700

4,557

14,700

= 0.3100 = 31 cM Correct distance =

½(2,130) + 3×(37 + 98)

14,700

1,065 + 405

14,700

1,470

14,700

= 0.1000 = 10 cM Incorrect distance =

½(2,130) + 3×(37)

14,700

1,065 + 111

14,700

1,176

14,700

= 0.0800 = 8 cM Incorrect distance =

½(5,364) + 3×(37)

14,700

2,682 + 111

14,700

2,793

14,700

= 0.1900 = 19 cM Incorrect distance =

½(5,364) + 3×(233)

14,700

2,682 + 699

14,700

3,381

14,700

= 0.2300 = 23 cM Incorrect MC

becf_429c

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is related to the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene R is correlated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,356

127

1,506

2,241

TOTAL =

5,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and Y

distance =

½(1,356) + 3×(72 + 98)

5,400

678 + 510

5,400

1,188

5,400

= 0.2200 = 22 cM Correct distance =

½(1,506) + 3×(72 + 127)

5,400

753 + 597

5,400

1,350

5,400

= 0.2500 = 25 cM Incorrect distance =

½(1,506) + 3×(127)

5,400

753 + 381

5,400

1,134

5,400

= 0.2100 = 21 cM Incorrect distance =

½(1,356 + 1,506) + 3×(72 + 98 + 127)

5,400

1,431 + 891

5,400

2,322

5,400

= 0.4300 = 43 cM Incorrect distance =

½(1,356) + 3×(98)

5,400

678 + 294

5,400

972

5,400

= 0.1800 = 18 cM Incorrect MC

0262_2076

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is related to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene E is associated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene Y is related to the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

2,208

248

5,280

6,552

TOTAL =

14,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and Y

distance =

½(2,208 + 5,280) + 3×(40 + 72 + 248)

14,400

3,744 + 1,080

14,400

4,824

14,400

= 0.3350 = 33.50 cM Incorrect distance =

½(5,280) + 3×(248)

14,400

2,640 + 744

14,400

3,384

14,400

= 0.2350 = 23.50 cM Incorrect distance =

½(2,208 + 5,280) + 3×(40 + 248)

14,400

3,744 + 864

14,400

4,608

14,400

= 0.3200 = 32 cM Correct distance =

½(5,280) + 3×(72 + 248)

14,400

2,640 + 960

14,400

3,600

14,400

= 0.2500 = 25 cM Incorrect distance =

½(2,208) + 3×(40 + 72)

14,400

1,104 + 336

14,400

1,440

14,400

= 0.1000 = 10 cM Incorrect MC

8f19_f198

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is linked with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene H is connected with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene T is related to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

116

3,354

6,885

5,394

370

TOTAL =

16,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and T

distance =

½(5,394) + 3×(81 + 370)

16,200

2,697 + 1,353

16,200

4,050

16,200

= 0.2500 = 25 cM Correct distance =

½(3,354 + 5,394) + 3×(81 + 116 + 370)

16,200

4,374 + 1,701

16,200

6,075

16,200

= 0.3750 = 37.50 cM Incorrect distance =

½(3,354 + 5,394) + 3×(81)

16,200

4,374 + 243

16,200

4,617

16,200

= 0.2850 = 28.50 cM Incorrect distance =

½(3,354 + 5,394) + 3×(116 + 370)

16,200

4,374 + 1,458

16,200

5,832

16,200

= 0.3600 = 36 cM Incorrect distance =

½(3,354) + 3×(81 + 116)

16,200

1,677 + 591

16,200

2,268

16,200

= 0.1400 = 14 cM Incorrect MC

6ec0_d48f

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is affiliated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene N is correlated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene R is linked with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

2,400

188

8,532

16,420

TOTAL =

27,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and R

distance =

½(2,400) + 3×(14 + 46)

27,600

1,200 + 180

27,600

1,380

27,600

= 0.0500 = 5 cM Incorrect distance =

½(2,400 + 8,532) + 3×(14 + 188)

27,600

5,466 + 606

27,600

6,072

27,600

= 0.2200 = 22 cM Correct distance =

½(8,532) + 3×(188)

27,600

4,266 + 564

27,600

4,830

27,600

= 0.1750 = 17.50 cM Incorrect distance =

½(8,532) + 3×(46 + 188)

27,600

4,266 + 702

27,600

4,968

27,600

= 0.1800 = 18 cM Incorrect distance =

½(2,400) + 3×(14)

27,600

1,200 + 42

27,600

1,242

27,600

= 0.0450 = 4.50 cM Incorrect MC

468e_50ef

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is connected with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene B is correlated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene M is related to the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

3,735

1,932

3,018

217

TOTAL =

9,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and M

distance =

½(3,018) + 3×(30 + 217)

9,000

1,509 + 741

9,000

2,250

9,000

= 0.2500 = 25 cM Incorrect distance =

½(1,932) + 3×(30 + 68)

9,000

966 + 294

9,000

1,260

9,000

= 0.1400 = 14 cM Correct distance =

½(1,932 + 3,018) + 3×(30 + 68 + 217)

9,000

2,475 + 945

9,000

3,420

9,000

= 0.3800 = 38 cM Incorrect distance =

½(1,932) + 3×(68)

9,000

966 + 204

9,000

1,170

9,000

= 0.1300 = 13 cM Incorrect distance =

½(1,932 + 3,018) + 3×(68 + 217)

9,000

2,475 + 855

9,000

3,330

9,000

= 0.3700 = 37 cM Incorrect MC

4953_5f70

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is analogous to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene N is connected with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene W is linked with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,176

6,890

4,086

TOTAL =

12,300

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and W

distance =

½(1,176) + 3×(9 + 41)

12,300

588 + 150

12,300

738

12,300

= 0.0600 = 6 cM Incorrect distance =

½(1,176 + 4,086) + 3×(9 + 98)

12,300

2,631 + 321

12,300

2,952

12,300

= 0.2400 = 24 cM Incorrect distance =

½(1,176 + 4,086) + 3×(9 + 41 + 98)

12,300

2,631 + 444

12,300

3,075

12,300

= 0.2500 = 25 cM Incorrect distance =

½(1,176) + 3×(9)

12,300

588 + 27

12,300

615

12,300

= 0.0500 = 5 cM Incorrect distance =

½(4,086) + 3×(41 + 98)

12,300

2,043 + 417

12,300

2,460

12,300

= 0.2000 = 20 cM Correct MC

3201_7963

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is connected with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene W is affiliated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

2,328

273

4,536

5,389

TOTAL =

12,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and W

distance =

½(2,328 + 4,536) + 3×(21 + 53)

12,600

3,432 + 222

12,600

3,654

12,600

= 0.2900 = 29 cM Incorrect distance =

½(2,328) + 3×(53 + 273)

12,600

1,164 + 978

12,600

2,142

12,600

= 0.1700 = 17 cM Incorrect distance =

½(2,328 + 4,536) + 3×(53 + 273)

12,600

3,432 + 978

12,600

4,410

12,600

= 0.3500 = 35 cM Correct distance =

½(2,328) + 3×(21 + 53)

12,600

1,164 + 222

12,600

1,386

12,600

= 0.1100 = 11 cM Incorrect distance =

½(4,536) + 3×(21 + 273)

12,600

2,268 + 882

12,600

3,150

12,600

= 0.2500 = 25 cM Incorrect MC

8a5d_bf13

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene X is connected with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

122

3,270

4,112

1,122

TOTAL =

8,700

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and X

distance =

½(3,270) + 3×(58 + 122)

8,700

1,635 + 540

8,700

2,175

8,700

= 0.2500 = 25 cM Correct distance =

½(1,122) + 3×(16 + 58)

8,700

561 + 222

8,700

783

8,700

= 0.0900 = 9 cM Incorrect distance =

½(3,270) + 3×(122)

8,700

1,635 + 366

8,700

2,001

8,700

= 0.2300 = 23 cM Incorrect distance =

½(1,122 + 3,270) + 3×(16 + 122)

8,700

2,196 + 414

8,700

2,610

8,700

= 0.3000 = 30 cM Incorrect distance =

½(1,122) + 3×(16)

8,700

561 + 48

8,700

609

8,700

= 0.0700 = 7 cM Incorrect MC

d297_fea9

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene J is correlated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene M is associated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene T is related to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

1,008

1,560

2,702

TOTAL =

5,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and M

distance =

½(1,008) + 3×(18 + 30)

5,400

504 + 144

5,400

648

5,400

= 0.1200 = 12 cM Incorrect distance =

½(1,560) + 3×(18 + 82)

5,400

780 + 300

5,400

1,080

5,400

= 0.2000 = 20 cM Incorrect distance =

½(1,008 + 1,560) + 3×(30 + 82)

5,400

1,284 + 336

5,400

1,620

5,400

= 0.3000 = 30 cM Correct distance =

½(1,008) + 3×(30)

5,400

504 + 90

5,400

594

5,400

= 0.1100 = 11 cM Incorrect distance =

½(1,008 + 1,560) + 3×(18 + 30 + 82)

5,400

1,284 + 390

5,400

1,674

5,400

= 0.3100 = 31 cM Incorrect MC

66e3_616b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene P is related to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene T is correlated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is linked with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

115

5,934

2,964

4,350

127

310

TOTAL =

13,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes T and W

distance =

½(4,350) + 3×(310)

13,800

2,175 + 930

13,800

3,105

13,800

= 0.2250 = 22.50 cM Incorrect distance =

½(4,350) + 3×(115 + 310)

13,800

2,175 + 1,275

13,800

3,450

13,800

= 0.2500 = 25 cM Correct distance =

½(2,964) + 3×(115 + 127)

13,800

1,482 + 726

13,800

2,208

13,800

= 0.1600 = 16 cM Incorrect distance =

½(2,964 + 4,350) + 3×(115)

13,800

3,657 + 345

13,800

4,002

13,800

= 0.2900 = 29 cM Incorrect distance =

½(2,964 + 4,350) + 3×(127 + 310)

13,800

3,657 + 1,311

13,800

4,968

13,800

= 0.3600 = 36 cM Incorrect MC

0a85_6f00

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is affiliated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is correlated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

4,308

5,250

816

TOTAL =

10,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and R

distance =

½(816) + 3×(4 + 35)

10,500

408 + 117

10,500

525

10,500

= 0.0500 = 5 cM Incorrect distance =

½(4,308) + 3×(35 + 87)

10,500

2,154 + 366

10,500

2,520

10,500

= 0.2400 = 24 cM Correct distance =

½(816) + 3×(4)

10,500

408 + 12

10,500

420

10,500

= 0.0400 = 4 cM Incorrect distance =

½(816 + 4,308) + 3×(4 + 35 + 87)

10,500

2,562 + 378

10,500

2,940

10,500

= 0.2800 = 28 cM Incorrect distance =

½(4,308) + 3×(87)

10,500

2,154 + 261

10,500

2,415

10,500

= 0.2300 = 23 cM Incorrect MC

e66d_8a8f

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene X is analogous to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.
Gene Y is affiliated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

101

4,752

19,879

3,372

TOTAL =

28,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and X

distance =

½(3,372 + 4,752) + 3×(49 + 101)

28,200

4,062 + 450

28,200

4,512

28,200

= 0.1600 = 16 cM Incorrect distance =

½(3,372) + 3×(49)

28,200

1,686 + 147

28,200

1,833

28,200

= 0.0650 = 6.50 cM Incorrect distance =

½(3,372 + 4,752) + 3×(47 + 49 + 101)

28,200

4,062 + 591

28,200

4,653

28,200

= 0.1650 = 16.50 cM Incorrect distance =

½(3,372) + 3×(47 + 49)

28,200

1,686 + 288

28,200

1,974

28,200

= 0.0700 = 7 cM Correct distance =

½(4,752) + 3×(47 + 101)

28,200

2,376 + 444

28,200

2,820

28,200

= 0.1000 = 10 cM Incorrect MC

186c_2538

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is correlated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene X is affiliated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

3,264

275

7,926

13,607

TOTAL =

25,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and R

distance =

½(3,264 + 7,926) + 3×(44 + 84 + 275)

25,200

5,595 + 1,209

25,200

6,804

25,200

= 0.2700 = 27 cM Incorrect distance =

½(3,264 + 7,926) + 3×(44 + 275)

25,200

5,595 + 957

25,200

6,552

25,200

= 0.2600 = 26 cM Incorrect distance =

½(3,264) + 3×(44 + 84)

25,200

1,632 + 384

25,200

2,016

25,200

= 0.0800 = 8 cM Correct distance =

½(7,926) + 3×(84 + 275)

25,200

3,963 + 1,077

25,200

5,040

25,200

= 0.2000 = 20 cM Incorrect distance =

½(3,264) + 3×(44)

25,200

1,632 + 132

25,200

1,764

25,200

= 0.0700 = 7 cM Incorrect MC

f072_2300

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is correlated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is related to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene X is associated with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

1,482

103

1,602

2,700

TOTAL =

6,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes R and X

distance =

½(1,482 + 1,602) + 3×(83 + 103)

6,000

1,542 + 558

6,000

2,100

6,000

= 0.3500 = 35 cM Correct distance =

½(1,602) + 3×(103)

6,000

801 + 309

6,000

1,110

6,000

= 0.1850 = 18.50 cM Incorrect distance =

½(1,602) + 3×(30 + 103)

6,000

801 + 399

6,000

1,200

6,000

= 0.2000 = 20 cM Incorrect distance =

½(1,482) + 3×(30 + 83)

6,000

741 + 339

6,000

1,080

6,000

= 0.1800 = 18 cM Incorrect distance =

½(1,602) + 3×(30 + 83)

6,000

801 + 339

6,000

1,140

6,000

= 0.1900 = 19 cM Incorrect MC

4aa4_ffc1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is related to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene C is associated with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene N is related to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

375

6,660

135

12,150

7,218

462

TOTAL =

27,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and N

distance =

½(6,660 + 7,218) + 3×(135 + 375 + 462)

27,000

6,939 + 2,916

27,000

9,855

27,000

= 0.3650 = 36.50 cM Incorrect distance =

½(6,660 + 7,218) + 3×(135)

27,000

6,939 + 405

27,000

7,344

27,000

= 0.2720 = 27.20 cM Incorrect distance =

½(6,660 + 7,218) + 3×(375 + 462)

27,000

6,939 + 2,511

27,000

9,450

27,000

= 0.3500 = 35 cM Incorrect distance =

½(6,660) + 3×(135 + 375)

27,000

3,330 + 1,530

27,000

4,860

27,000

= 0.1800 = 18 cM Incorrect distance =

½(7,218) + 3×(135 + 462)

27,000

3,609 + 1,791

27,000

5,400

27,000

= 0.2000 = 20 cM Correct MC

f31a_2eb2

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is associated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene K is correlated with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene T is connected with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

624

1,386

1,783

TOTAL =

3,900

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes K and T

distance =

½(1,386) + 3×(26 + 68)

3,900

693 + 282

3,900

975

3,900

= 0.2500 = 25 cM Incorrect distance =

½(624) + 3×(13)

3,900

312 + 39

3,900

351

3,900

= 0.0900 = 9 cM Incorrect distance =

½(624 + 1,386) + 3×(68)

3,900

1,005 + 204

3,900

1,209

3,900

= 0.3100 = 31 cM Incorrect distance =

½(624 + 1,386) + 3×(13 + 68)

3,900

1,005 + 243

3,900

1,248

3,900

= 0.3200 = 32 cM Correct distance =

½(1,386) + 3×(13 + 26 + 68)

3,900

693 + 321

3,900

1,014

3,900

= 0.2600 = 26 cM Incorrect MC

eb02_126a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene J is correlated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene M is connected with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

2,598

8,370

7,260

309

TOTAL =

18,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes J and M

distance =

½(2,598 + 7,260) + 3×(31 + 32 + 309)

18,600

4,929 + 1,116

18,600

6,045

18,600

= 0.3250 = 32.50 cM Incorrect distance =

½(2,598 + 7,260) + 3×(32 + 309)

18,600

4,929 + 1,023

18,600

5,952

18,600

= 0.3200 = 32 cM Correct distance =

½(2,598 + 7,260) + 3×(31)

18,600

4,929 + 93

18,600

5,022

18,600

= 0.2700 = 27 cM Incorrect distance =

½(2,598) + 3×(31 + 32)

18,600

1,299 + 189

18,600

1,488

18,600

= 0.0800 = 8 cM Incorrect distance =

½(7,260) + 3×(31 + 309)

18,600

3,630 + 1,020

18,600

4,650

18,600

= 0.2500 = 25 cM Incorrect MC

2883_625f

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene R is affiliated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene T is correlated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

551

7,128

9,102

5,082

111

226

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes R and W

distance =

½(5,082 + 7,128) + 3×(111)

22,200

6,105 + 333

22,200

6,438

22,200

= 0.2900 = 29 cM Incorrect distance =

½(5,082 + 7,128) + 3×(226 + 551)

22,200

6,105 + 2,331

22,200

8,436

22,200

= 0.3800 = 38 cM Incorrect distance =

½(5,082 + 7,128) + 3×(111 + 226 + 551)

22,200

6,105 + 2,664

22,200

8,769

22,200

= 0.3950 = 39.50 cM Incorrect distance =

½(7,128) + 3×(111 + 551)

22,200

3,564 + 1,986

22,200

5,550

22,200

= 0.2500 = 25 cM Correct distance =

½(5,082) + 3×(111 + 226)

22,200

2,541 + 1,011

22,200

3,552

22,200

= 0.1600 = 16 cM Incorrect MC

a43a_a8d0

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene W is related to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene X is linked with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

124

2,400

8,791

6,990

261

TOTAL =

18,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and X

distance =

½(2,400 + 6,990) + 3×(34 + 261)

18,600

4,695 + 885

18,600

5,580

18,600

= 0.3000 = 30 cM Correct distance =

½(2,400 + 6,990) + 3×(34 + 124 + 261)

18,600

4,695 + 1,257

18,600

5,952

18,600

= 0.3200 = 32 cM Incorrect distance =

½(2,400) + 3×(34 + 124)

18,600

1,200 + 474

18,600

1,674

18,600

= 0.0900 = 9 cM Incorrect distance =

½(6,990) + 3×(261)

18,600

3,495 + 783

18,600

4,278

18,600

= 0.2300 = 23 cM Incorrect distance =

½(2,400) + 3×(34)

18,600

1,200 + 102

18,600

1,302

18,600

= 0.0700 = 7 cM Incorrect MC

8b64_3492

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene C is linked with the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene D is analogous to the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene X is connected with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

1,914

141

3,150

5,770

TOTAL =

11,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes C and D

distance =

½(3,150) + 3×(141)

11,100

1,575 + 423

11,100

1,998

11,100

= 0.1800 = 18 cM Incorrect distance =

½(1,914) + 3×(51)

11,100

957 + 153

11,100

1,110

11,100

= 0.1000 = 10 cM Incorrect distance =

½(1,914 + 3,150) + 3×(51 + 74 + 141)

11,100

2,532 + 798

11,100

3,330

11,100

= 0.3000 = 30 cM Incorrect distance =

½(3,150) + 3×(74 + 141)

11,100

1,575 + 645

11,100

2,220

11,100

= 0.2000 = 20 cM Incorrect distance =

½(1,914) + 3×(51 + 74)

11,100

957 + 375

11,100

1,332

11,100

= 0.1200 = 12 cM Correct MC

bad6_7735

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is analogous to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene D is associated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

223

5,544

9,858

2,826

TOTAL =

18,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and P

distance =

½(5,544) + 3×(93 + 223)

18,600

2,772 + 948

18,600

3,720

18,600

= 0.2000 = 20 cM Incorrect distance =

½(2,826) + 3×(56 + 93)

18,600

1,413 + 447

18,600

1,860

18,600

= 0.1000 = 10 cM Incorrect distance =

½(2,826) + 3×(56)

18,600

1,413 + 168

18,600

1,581

18,600

= 0.0850 = 8.50 cM Incorrect distance =

½(2,826 + 5,544) + 3×(93)

18,600

4,185 + 279

18,600

4,464

18,600

= 0.2400 = 24 cM Incorrect distance =

½(2,826 + 5,544) + 3×(56 + 223)

18,600

4,185 + 837

18,600

5,022

18,600

= 0.2700 = 27 cM Correct MC

a255_9ce3

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene N is related to the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.
Gene W is analogous to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

267

9,396

15,508

2,958

TOTAL =

28,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes N and W

distance =

½(2,958) + 3×(24)

28,200

1,479 + 72

28,200

1,551

28,200

= 0.0550 = 5.50 cM Incorrect distance =

½(9,396) + 3×(47 + 267)

28,200

4,698 + 942

28,200

5,640

28,200

= 0.2000 = 20 cM Correct distance =

½(2,958 + 9,396) + 3×(24 + 47 + 267)

28,200

6,177 + 1,014

28,200

7,191

28,200

= 0.2550 = 25.50 cM Incorrect distance =

½(2,958) + 3×(24 + 47)

28,200

1,479 + 213

28,200

1,692

28,200

= 0.0600 = 6 cM Incorrect distance =

½(2,958 + 9,396) + 3×(24 + 267)

28,200

6,177 + 873

28,200

7,050

28,200

= 0.2500 = 25 cM Incorrect MC

2e59_72fc

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is correlated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene R is analogous to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene X is analogous to the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

174

5,220

13,175

2,946

TOTAL =

21,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and R

distance =

½(5,220) + 3×(174)

21,600

2,610 + 522

21,600

3,132

21,600

= 0.1450 = 14.50 cM Incorrect distance =

½(2,946) + 3×(36 + 49)

21,600

1,473 + 255

21,600

1,728

21,600

= 0.0800 = 8 cM Correct distance =

½(5,220) + 3×(36 + 174)

21,600

2,610 + 630

21,600

3,240

21,600

= 0.1500 = 15 cM Incorrect distance =

½(2,946 + 5,220) + 3×(36 + 49 + 174)

21,600

4,083 + 777

21,600

4,860

21,600

= 0.2250 = 22.50 cM Incorrect distance =

½(2,946 + 5,220) + 3×(49 + 174)

21,600

4,083 + 669

21,600

4,752

21,600

= 0.2200 = 22 cM Incorrect MC

4b30_95f7

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is linked with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene H is associated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene T is connected with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

365

7,500

13,005

4,434

111

TOTAL =

25,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and T

distance =

½(4,434 + 7,500) + 3×(85 + 111 + 365)

25,500

5,967 + 1,683

25,500

7,650

25,500

= 0.3000 = 30 cM Incorrect distance =

½(4,434 + 7,500) + 3×(111 + 365)

25,500

5,967 + 1,428

25,500

7,395

25,500

= 0.2900 = 29 cM Incorrect distance =

½(7,500) + 3×(85 + 365)

25,500

3,750 + 1,350

25,500

5,100

25,500

= 0.2000 = 20 cM Correct distance =

½(4,434) + 3×(85 + 111)

25,500

2,217 + 588

25,500

2,805

25,500

= 0.1100 = 11 cM Incorrect distance =

½(7,500) + 3×(365)

25,500

3,750 + 1,095

25,500

4,845

25,500

= 0.1900 = 19 cM Incorrect MC

080b_2221

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is correlated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene R is related to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene T is analogous to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

1,980

186

9,594

13,645

TOTAL =

25,500

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and R

distance =

½(1,980 + 9,594) + 3×(10 + 186)

25,500

5,787 + 588

25,500

6,375

25,500

= 0.2500 = 25 cM Incorrect distance =

½(9,594) + 3×(85 + 186)

25,500

4,797 + 813

25,500

5,610

25,500

= 0.2200 = 22 cM Incorrect distance =

½(1,980) + 3×(10)

25,500

990 + 30

25,500

1,020

25,500

= 0.0400 = 4 cM Incorrect distance =

½(1,980) + 3×(10 + 85)

25,500

990 + 285

25,500

1,275

25,500

= 0.0500 = 5 cM Correct distance =

½(1,980 + 9,594) + 3×(10 + 85 + 186)

25,500

5,787 + 843

25,500

6,630

25,500

= 0.2600 = 26 cM Incorrect MC

5d8b_9f6a

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is analogous to the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene K is connected with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene P is linked with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.

Set #

Tetrad Genotypes

Progeny
Count

864

1,914

2,473

TOTAL =

5,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes A and K

distance =

½(1,914) + 3×(18 + 95)

5,400

957 + 339

5,400

1,296

5,400

= 0.2400 = 24 cM Incorrect distance =

½(1,914) + 3×(95)

5,400

957 + 285

5,400

1,242

5,400

= 0.2300 = 23 cM Incorrect distance =

½(864 + 1,914) + 3×(18 + 95)

5,400

1,389 + 339

5,400

1,728

5,400

= 0.3200 = 32 cM Correct distance =

½(864 + 1,914) + 3×(36 + 95)

5,400

1,389 + 393

5,400

1,782

5,400

= 0.3300 = 33 cM Incorrect distance =

½(1,914) + 3×(36 + 95)

5,400

957 + 393

5,400

1,350

5,400

= 0.2500 = 25 cM Incorrect MC

a9fe_a55d

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is associated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene W is analogous to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.
Gene X is linked with the 'xenon' phenotype. A budding yeast that is homozygous recessive for Gene X cells emit a faint glow under UV light, as if they were fluorescent.

Set #

Tetrad Genotypes

Progeny
Count

459

10,770

12,420

3,858

TOTAL =

27,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes W and X

distance =

½(3,858 + 10,770) + 3×(47 + 459)

27,600

7,314 + 1,518

27,600

8,832

27,600

= 0.3200 = 32 cM Correct distance =

½(3,858 + 10,770) + 3×(46)

27,600

7,314 + 138

27,600

7,452

27,600

= 0.2700 = 27 cM Incorrect distance =

½(3,858) + 3×(46 + 47)

27,600

1,929 + 279

27,600

2,208

27,600

= 0.0800 = 8 cM Incorrect distance =

½(10,770) + 3×(46 + 459)

27,600

5,385 + 1,515

27,600

6,900

27,600

= 0.2500 = 25 cM Incorrect distance =

½(10,770) + 3×(459)

27,600

5,385 + 1,377

27,600

6,762

27,600

= 0.2450 = 24.50 cM Incorrect MC

c397_e86b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is connected with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene M is linked with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.
Gene Y is correlated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

702

4,815

3,384

TOTAL =

9,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and M

distance =

½(702 + 3,384) + 3×(3 + 66)

9,000

2,043 + 207

9,000

2,250

9,000

= 0.2500 = 25 cM Incorrect distance =

½(702) + 3×(3 + 30)

9,000

351 + 99

9,000

450

9,000

= 0.0500 = 5 cM Correct distance =

½(702) + 3×(3)

9,000

351 + 9

9,000

360

9,000

= 0.0400 = 4 cM Incorrect distance =

½(702 + 3,384) + 3×(3 + 30 + 66)

9,000

2,043 + 297

9,000

2,340

9,000

= 0.2600 = 26 cM Incorrect distance =

½(3,384) + 3×(30 + 66)

9,000

1,692 + 288

9,000

1,980

9,000

= 0.2200 = 22 cM Incorrect MC

7131_3d45

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is associated with the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene C is analogous to the 'clumpy' phenotype. A budding yeast that is homozygous recessive for Gene C grows in dense, irregular clusters, with cells clumping together rather than spreading smoothly.
Gene N is associated with the 'nude' phenotype. A budding yeast that is homozygous recessive for Gene N cells have an unusually smooth surface with no visible external features or textures.

Set #

Tetrad Genotypes

Progeny
Count

140

3,042

9,765

7,668

332

TOTAL =

21,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes B and C

distance =

½(3,042 + 7,668) + 3×(53 + 332)

21,000

5,355 + 1,155

21,000

6,510

21,000

= 0.3100 = 31 cM Incorrect distance =

½(3,042) + 3×(53 + 140)

21,000

1,521 + 579

21,000

2,100

21,000

= 0.1000 = 10 cM Correct distance =

½(7,668) + 3×(332)

21,000

3,834 + 996

21,000

4,830

21,000

= 0.2300 = 23 cM Incorrect distance =

½(7,668) + 3×(140 + 332)

21,000

3,834 + 1,416

21,000

5,250

21,000

= 0.2500 = 25 cM Incorrect distance =

½(3,042) + 3×(53)

21,000

1,521 + 159

21,000

1,680

21,000

= 0.0800 = 8 cM Incorrect MC

03fa_84d2

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is analogous to the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene F is linked with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene M is affiliated with the 'militant' phenotype. A budding yeast that is homozygous recessive for Gene M colonies are small, dense, and secrete compounds that inhibit the growth of nearby colonies.

Set #

Tetrad Genotypes

Progeny
Count

1,014

3,003

2,418

114

TOTAL =

6,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and F

distance =

½(1,014 + 2,418) + 3×(18 + 114)

6,600

1,716 + 396

6,600

2,112

6,600

= 0.3200 = 32 cM Incorrect distance =

½(2,418) + 3×(33 + 114)

6,600

1,209 + 441

6,600

1,650

6,600

= 0.2500 = 25 cM Incorrect distance =

½(1,014) + 3×(18)

6,600

507 + 54

6,600

561

6,600

= 0.0850 = 8.50 cM Incorrect distance =

½(2,418) + 3×(114)

6,600

1,209 + 342

6,600

1,551

6,600

= 0.2350 = 23.50 cM Incorrect distance =

½(1,014) + 3×(18 + 33)

6,600

507 + 153

6,600

660

6,600

= 0.1000 = 10 cM Correct MC

38d8_5ed1

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene B is related to the 'bubbly' phenotype. A budding yeast that is homozygous recessive for Gene B produces excessive gas bubbles during growth, causing foamy appearance of the media.
Gene F is analogous to the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene T is affiliated with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

169

2,748

2,202

4,653

TOTAL =

9,900

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and T

distance =

½(2,202 + 2,748) + 3×(33)

9,900

2,475 + 99

9,900

2,574

9,900

= 0.2600 = 26 cM Incorrect distance =

½(2,202) + 3×(33 + 95)

9,900

1,101 + 384

9,900

1,485

9,900

= 0.1500 = 15 cM Incorrect distance =

½(2,202 + 2,748) + 3×(95 + 169)

9,900

2,475 + 792

9,900

3,267

9,900

= 0.3300 = 33 cM Incorrect distance =

½(2,748) + 3×(169)

9,900

1,374 + 507

9,900

1,881

9,900

= 0.1900 = 19 cM Incorrect distance =

½(2,748) + 3×(33 + 169)

9,900

1,374 + 606

9,900

1,980

9,900

= 0.2000 = 20 cM Correct MC

dffc_e9d3

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene E is connected with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene J is correlated with the 'jeweled' phenotype. A budding yeast that is homozygous recessive for Gene J colonies appear dotted with tiny, iridescent spots that sparkle under light.
Gene R is analogous to the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.

Set #

Tetrad Genotypes

Progeny
Count

882

1,230

738

TOTAL =

3,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes E and J

distance =

½(738 + 882) + 3×(47 + 73)

3,000

810 + 360

3,000

1,170

3,000

= 0.3900 = 39 cM Incorrect distance =

½(738 + 882) + 3×(30)

3,000

810 + 90

3,000

900

3,000

= 0.3000 = 30 cM Incorrect distance =

½(882) + 3×(73)

3,000

441 + 219

3,000

660

3,000

= 0.2200 = 22 cM Incorrect distance =

½(738) + 3×(30 + 47)

3,000

369 + 231

3,000

600

3,000

= 0.2000 = 20 cM Correct distance =

½(882) + 3×(30 + 73)

3,000

441 + 309

3,000

750

3,000

= 0.2500 = 25 cM Incorrect MC

cfa4_17c0

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is affiliated with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene E is affiliated with the 'elephant' phenotype. A budding yeast that is homozygous recessive for Gene E cells absorb excessive amounts of liquid, resulting in giant, swollen cells.
Gene T is linked with the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.

Set #

Tetrad Genotypes

Progeny
Count

6,000

2,244

3,468

182

TOTAL =

12,000

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes D and E

distance =

½(2,244 + 3,468) + 3×(40 + 66 + 182)

12,000

2,856 + 864

12,000

3,720

12,000

= 0.3100 = 31 cM Incorrect distance =

½(3,468) + 3×(40 + 182)

12,000

1,734 + 666

12,000

2,400

12,000

= 0.2000 = 20 cM Incorrect distance =

½(2,244) + 3×(66)

12,000

1,122 + 198

12,000

1,320

12,000

= 0.1100 = 11 cM Incorrect distance =

½(2,244 + 3,468) + 3×(66 + 182)

12,000

2,856 + 744

12,000

3,600

12,000

= 0.3000 = 30 cM Correct distance =

½(2,244) + 3×(40 + 66)

12,000

1,122 + 318

12,000

1,440

12,000

= 0.1200 = 12 cM Incorrect MC

2393_fb2d

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene D is linked with the 'doubled' phenotype. A budding yeast that is homozygous recessive for Gene D cells display double or multiple budding, with several buds emerging simultaneously.
Gene F is linked with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene H is associated with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.

Set #

Tetrad Genotypes

Progeny
Count

2,256

12,193

11,028

269

TOTAL =

25,800

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and H

distance =

½(11,028) + 3×(43 + 269)

25,800

5,514 + 936

25,800

6,450

25,800

= 0.2500 = 25 cM Incorrect distance =

½(2,256) + 3×(43 + 269)

25,800

1,128 + 936

25,800

2,064

25,800

= 0.0800 = 8 cM Incorrect distance =

½(11,028) + 3×(11 + 43)

25,800

5,514 + 162

25,800

5,676

25,800

= 0.2200 = 22 cM Incorrect distance =

½(2,256 + 11,028) + 3×(11 + 269)

25,800

6,642 + 840

25,800

7,482

25,800

= 0.2900 = 29 cM Correct distance =

½(2,256) + 3×(11 + 43)

25,800

1,128 + 162

25,800

1,290

25,800

= 0.0500 = 5 cM Incorrect MC

4dba_00b2

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene H is linked with the 'hairy' phenotype. A budding yeast that is homozygous recessive for Gene H cells develop long, thread-like filaments that extend outward, creating a hairy, shaggy texture on the colony.
Gene P is connected with the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene Y is connected with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

1,356

1,701

462

TOTAL =

3,600

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes H and P

distance =

½(1,356) + 3×(24 + 50)

3,600

678 + 222

3,600

900

3,600

= 0.2500 = 25 cM Incorrect distance =

½(462) + 3×(7 + 24)

3,600

231 + 93

3,600

324

3,600

= 0.0900 = 9 cM Correct distance =

½(1,356) + 3×(50)

3,600

678 + 150

3,600

828

3,600

= 0.2300 = 23 cM Incorrect distance =

½(462 + 1,356) + 3×(7 + 24 + 50)

3,600

909 + 243

3,600

1,152

3,600

= 0.3200 = 32 cM Incorrect distance =

½(462) + 3×(7)

3,600

231 + 21

3,600

252

3,600

= 0.0700 = 7 cM Incorrect MC

50fc_456b

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene T is analogous to the 'toxic' phenotype. A budding yeast that is homozygous recessive for Gene T secretes a toxic compound that inhibits or kills other microbial colonies nearby.
Gene W is associated with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

1,758

2,568

6,607

TOTAL =

11,100

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes T and W

distance =

½(2,568) + 3×(37 + 90)

11,100

1,284 + 381

11,100

1,665

11,100

= 0.1500 = 15 cM Incorrect distance =

½(1,758) + 3×(37 + 40)

11,100

879 + 231

11,100

1,110

11,100

= 0.1000 = 10 cM Incorrect distance =

½(2,568) + 3×(90)

11,100

1,284 + 270

11,100

1,554

11,100

= 0.1400 = 14 cM Incorrect distance =

½(1,758 + 2,568) + 3×(40 + 90)

11,100

2,163 + 390

11,100

2,553

11,100

= 0.2300 = 23 cM Correct distance =

½(1,758 + 2,568) + 3×(37 + 40 + 90)

11,100

2,163 + 501

11,100

2,664

11,100

= 0.2400 = 24 cM Incorrect MC

052d_f7e5

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene K is linked with the 'knotted' phenotype. A budding yeast that is homozygous recessive for Gene K cells grow in twisted, coiled shapes, resulting in a knotted or gnarled appearance.
Gene P is analogous to the 'pebble' phenotype. A budding yeast that is homozygous recessive for Gene P produces colonies with a rough, uneven surface that resembles a collection of tiny pebbles.
Gene W is connected with the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

117

3,882

175

5,268

13,864

TOTAL =

23,400

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes P and W

distance =

½(3,882) + 3×(94 + 117)

23,400

1,941 + 633

23,400

2,574

23,400

= 0.1100 = 11 cM Incorrect distance =

½(5,268) + 3×(175)

23,400

2,634 + 525

23,400

3,159

23,400

= 0.1350 = 13.50 cM Incorrect distance =

½(3,882 + 5,268) + 3×(94 + 175)

23,400

4,575 + 807

23,400

5,382

23,400

= 0.2300 = 23 cM Correct distance =

½(5,268) + 3×(117 + 175)

23,400

2,634 + 876

23,400

3,510

23,400

= 0.1500 = 15 cM Incorrect distance =

½(3,882 + 5,268) + 3×(94 + 117 + 175)

23,400

4,575 + 1,158

23,400

5,733

23,400

= 0.2450 = 24.50 cM Incorrect MC

786a_d792

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene F is affiliated with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene R is correlated with the 'rusty' phenotype. A budding yeast that is homozygous recessive for Gene R colonies develop a reddish-brown pigmentation, reminiscent of rusted metal.
Gene W is analogous to the 'webbed' phenotype. A budding yeast that is homozygous recessive for Gene W colonies produce delicate, web-like strands that connect neighboring colonies in a cobweb pattern.

Set #

Tetrad Genotypes

Progeny
Count

816

894

1,588

TOTAL =

3,450

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and R

distance =

½(894) + 3×(46 + 58)

3,450

447 + 312

3,450

759

3,450

= 0.2200 = 22 cM Incorrect distance =

½(816) + 3×(46 + 48)

3,450

408 + 282

3,450

690

3,450

= 0.2000 = 20 cM Correct distance =

½(816) + 3×(48)

3,450

408 + 144

3,450

552

3,450

= 0.1600 = 16 cM Incorrect distance =

½(816 + 894) + 3×(46 + 48 + 58)

3,450

855 + 456

3,450

1,311

3,450

= 0.3800 = 38 cM Incorrect distance =

½(816 + 894) + 3×(48 + 58)

3,450

855 + 318

3,450

1,173

3,450

= 0.3400 = 34 cM Incorrect MC

c3a3_d40d

Unordered Tetrad Three Gene Mapping

Characteristics of Recessive Phenotypes

Gene A is associated with the 'amber' phenotype. A budding yeast that is homozygous recessive for Gene A cells develop a rich yellow-orange pigmentation, giving the colony a warm, amber hue.
Gene F is connected with the 'fuzzy' phenotype. A budding yeast that is homozygous recessive for Gene F colonies are covered in soft, fine filaments, giving them a fuzzy, cotton-like texture.
Gene Y is correlated with the 'yolk' phenotype. A budding yeast that is homozygous recessive for Gene Y cells develop a dense, yellowish core that resembles an egg yolk when viewed under a microscope.

Set #

Tetrad Genotypes

Progeny
Count

2,292

15,983

3,792

TOTAL =

22,200

The resulting phenotypes are summarized in the table above.

Step-by-Step Instructions

Step 1: Find the row for the Parental Type for all three genes.
Step 2: Looking at only your two genes, assign PD, NPD, TT.
Step 3: Determine if the two genes are linked.

PD >> NPD → linked; PD ≈ NPD → unlinked

Step 4: Determine the map distance between the two genes.

D = ½ (TT + 6 NPD) / total = (3 NPD + ½ TT) / total

Determine the distance between the two genes F and Y

distance =

½(2,292 + 3,792) + 3×(25 + 71)

22,200

3,042 + 288

22,200

3,330

22,200

= 0.1500 = 15 cM Correct distance =

½(3,792) + 3×(37 + 71)

22,200

1,896 + 324

22,200

2,220

22,200

= 0.1000 = 10 cM Incorrect distance =

½(2,292) + 3×(25)

22,200

1,146 + 75

22,200

1,221

22,200

= 0.0550 = 5.50 cM Incorrect distance =

½(2,292 + 3,792) + 3×(25 + 37 + 71)

22,200

3,042 + 399

22,200

3,441

22,200

= 0.1550 = 15.50 cM Incorrect distance =

½(2,292) + 3×(25 + 37)

22,200

1,146 + 186

22,200

1,332

22,200

= 0.0600 = 6 cM Incorrect