6: Chromosomal Inheritance
Chromosome behavior in meiosis, sex-linkage, and the chromosomal basis of inheritance.
LibreTexts reference: Chromosomal Inheritance
Matching Meiosis Prophase I Stages to Descriptions
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Match each of the following stages of meiosis prophase I with their corresponding partial descriptions.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. Diplotene and/or Diakinesis | ||
| 2. Early/Late Pachytene | ||
| 3. Zygotene | ||
| 4. Leptotene |
Drag one of the choices below:
- A. chromosomes first become visible in the form of thread-like structures
- B. the swapping of genetic material occurs at the chiasmata
- C. the paired chromosomes being to separate
- D. the pairing of homologous chromosomes begins
Matching Meiosis Terms to Definitions
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Match each of the following Meiosis terms with their corresponding definitions.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. homologous chromosomes | ||
| 2. crossing over | ||
| 3. sister chromatids | ||
| 4. homologous |
Drag one of the choices below:
- A. two chromosomes containing identical genetic loci although possibly different allelic forms
- B. two homologous chromosomes line up and parts of the chromosomes can be exchanged
- C. two identical copies of the same chromosome formed by DNA replication
- D. corresponding or alike in certain critical attributes
Matching Sex Determination Systems to Descriptions
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Match each of the following sex determination systems with their corresponding descriptions.
Note: Each choice will be used exactly once.
| Your Choice | Prompt | |
|---|---|---|
| 1. Haplo-Diploid system | ||
| 2. X-O system | ||
| 3. Z-W system | ||
| 4. X-Y system |
Drag one of the choices below:
- A. there are no sex chromosomes
- B. males ♂ have two different kinds of chromosomes
- C. this system is the reverse of the system found in humans
- D. females ♀ have two homologous sex chromosomes, males ♂ have only one
Identifying Meiosis Prophase I Stages
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Which one of the following stages of meiosis prophase I correspond to the partial description 'exchange of segments between chromatids may occur'.
Identifying Meiosis Terms
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Which one of the following Meiosis terms correspond to the definition 'the point of contact (or physical link) between two homologous chromosomes where crossing over occurs'.
Identifying Sex Determination Systems
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Which one of the following sex determination systems correspond to the description 'found in most birds, many reptiles, and some insects'.
Determining True/False Statements About Mitosis and Meiosis
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Which one of the following statements is TRUE of mitosis and meiosis cell division?
Determining Inheritance Patterns for X-Linked Recessive and Autosomal Dominant Disorders
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Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder that is caused by mutations in the DMD gene. This results in dystrophin is responsible for connecting the actin cytoskeleton to the extracellular matrix (ECM) in muscle cells. The disorder affects 1 in 20,000 males. Individuals affected with DMD have muscle weakness, trouble standing up, which eventually leads to loss of skeletal muscle control, respiratory failure, and death. The defective gene for DMD is located on the short arm of chromosome X at position 21.2.
Achondroplasia is an autosomal dominant genetic disorder that is caused by a mutation in the FGFR3 gene. This results in a mutated protein that interacts negatively with growth factors leading to complications with bone production. The disorder affects 1 in 27,500 people. Individuals affected with achondroplasia have dwarfism with short arms and legs, an enlarged head, and a prominent forehead. The defective gene for achondroplasia is located on the short arm of chromosome 4 at position 16.3.
A man (♂) with both DMD and achondroplasia genetic disorders marries a wild-type phenotype woman (♀) with neither disorder. The father (♂) of the woman has the DMD genetic disorder,but mother (♀) of the woman does not. The mother (♀) of the man is wild-type phenotype and does not have the achondroplasia genetic disorder.
Reminder: DMD is X-linked recessive and achondroplasia is autosomal dominant.
What fraction of their sons (♂) will have both DMD and achondroplasia genetic disorders?
Identifying Inheritance Patterns from Pedigree Charts
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