4: Mendelian Genetics
Students predict offspring ratios using Punnett squares, apply Mendel's principles of segregation and independent assortment, and trace traits through pedigrees.
LibreTexts reference: Chapter 4: Mendelian Genetics 
Mendelian Cross Generations and Descriptions
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Match each of the following Mendelian crosses and generational stages with their corresponding descriptions.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. F1 generation | ||
| 2. reciprocal cross | ||
| 3. F2 generation | ||
| 4. P generation | ||
| 5. backcross |
Drag one of the choices below:
- A. the first generational step in assessing genetic variance, originating from the parental generation
- B. the second generation in a cross; the offspring of the F1 generation generation
- C. the initial generation of a hybrid cross that includes two homozygous, true-breeding organisms with distinct phenotype
- D. a type of cross where F1 generation hybrids are crossed with one of the parental genotype
- E. a type of cross designed to test the role of parental sex on a given inheritance pattern
Mendel's Foundational Principles and Descriptions
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Match each of the following Mendel's Foundational Principles of Genetics with their corresponding descriptions.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. Law of Segregation | ||
| 2. Law of Independent Assortment | ||
| 3. Principle of Dominance | ||
| 4. Principle of Paired Factors |
Drag one of the choices below:
- A. For each characters there is a dominant allele, the phenotype is determined by that allele.
- B. The genetic makeup for each character involves two alleles.
- C. When the gametes are formed, the factors separate and are distributed as units to each gamete.
- D. The inheritance of one trait doesn't influence the inheritance of another.
Mendelian Genetics Terms and Definitions
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Match each of the following Mendelian genetics terms with their corresponding definitions.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. heterozygous | ||
| 2. dominant | ||
| 3. phenotype | ||
| 4. alleles | ||
| 5. recessive |
Drag one of the choices below:
- A. one of two or more versions of DNA sequence at a given genomic location
- B. two different alleles for a gene
- C. manifestation of DNA as observable traits
- D. describes a trait whose expression is masked by another trait when the alleles for both traits are present
- E. describes a trait that masks the expression of another trait when both versions of the gene are present
Monohybrid Cross Genotypes and Phenotypes
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Match each of the following parental genotypes in monohybrid crosses with their corresponding descriptions of the progeny.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. AA×aa | ||
| 2. aa×aa | ||
| 3. AA×Aa | ||
| 4. Aa×aa | ||
| 5. AA×AA | ||
| 6. Aa×Aa |
Drag one of the choices below:
- A. All offspring have the same recessive genotype and phenotype
- B. All offspring have the same dominant genotype and phenotype
- C. 25% of the offspring are homozygous dominant
- D. Produces a 1:1 phenotype ratio in progeny
- E. All offspring have the dominant phenotype and are heterozygous
- F. Yields offspring with 50% homozygous dominant and 50% heterozygous genotypes
Mendelian Cross Generations
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Which one of the following Mendelian crosses and generational stages correspond to the description 'a type of cross where a test organism showing a dominant trait is crossed with one showing all recessive traits'.
Mendel's Foundational Principles
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Which one of the following Mendel's Foundational Principles of Genetics correspond to the description 'The segregation of one gene pair doesn't affect the segregation of another.'.
Mendelian Genetics Terms
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Which one of the following Mendelian genetics terms correspond to the definition 'a general term for either male (sperm) or female (egg) germ cells, which unite to form the zygote'.
Monohybrid Cross Genotype Outcomes
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Which one of the following parental genotypes in monohybrid crosses correspond to the description of the progeny '25% of the offspring are homozygous dominant'.
Determining Dominance Type in Monohybrid Crosses
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| Gene 1 | Female ♀ | ||
|---|---|---|---|
| A | a | ||
|
Male ♂ | A | AA |
❉❉❉❉❉❉ ❉❉ Aa ❉❉ ❉❉❉❉❉❉ |
| a |
❉❉❉❉❉❉ ❉❉ Aa ❉❉ ❉❉❉❉❉❉ | aa | |
Two organisms were crossed in a monohybrid experiment. The offspring phenotypes included white (■) and blue (■), along with a speckled combination of white (■) and blue (■).
What type of dominance best explains these results?
Monohybrid Cross Outcomes
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Determining Parent Genotype from Offspring Ratios
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A true-breeding mouse with brown fur is crossed with an individual of unknown genotype. In a large litter of 10 offspring, 0 show black fur and 10 show brown fur.
Assume a single gene with A dominant to a. What is the most likely genotype of the unknown parent?
Punnett Square Results for Flower Color Inheritance
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Inheritance Patterns from Pedigrees
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Examine the pedigree above. Which one of the following patterns of inheritance is most likely demonstrated in the above pedigree inheritance?
Matching Pedigrees to Inheritance Patterns
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Match the following pedigrees to their most likely inheritance type.
Note: each inheritance type will only be used ONCE.
| Your Choice | Prompt | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1.
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2.
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3.
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5.
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Drag one of the choices below:
- A. x-linked dominant
- B. autosomal dominant
- C. x-linked recessive
- D. autosomal recessive
- E. y-linked
Matching Pedigrees to Inheritance Patterns
Click to show Matching Pedigrees to Inheritance Patterns example problem
Match the following pedigrees to their most likely inheritance type.
Note: each inheritance type will only be used ONCE.
| Your Choice | Prompt | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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1.
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2.
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3.
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4.
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5.
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Drag one of the choices below:
- A. autosomal recessive
- B. x-linked recessive
- C. x-linked dominant
- D. autosomal dominant
- E. y-linked