Table of contents

1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

3. Extensions to Mendelian Inheritance

Sex Chromosome

Genetics

3. Extensions to Mendelian Inheritance

Sex Chromosome

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Multiple Choice

In humans, if a non-disjunction event led to an individual with a genotype of XXY, they would:

have Down syndrome

develop Turner syndrome

have Klinefelter syndrome

be phenotypically female with normal fertility

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Verified step by step guidance

Understand the concept of nondisjunction: it is an error in meiosis where chromosomes fail to separate properly, leading to gametes with abnormal numbers of chromosomes.

Recall the typical human sex chromosome combinations: XX for females and XY for males.

Recognize that an individual with the genotype XXY has an extra X chromosome, which is a common example of a sex chromosome aneuploidy.

Identify the syndromes associated with sex chromosome aneuploidies: Turner syndrome is associated with a single X chromosome (XO), Down syndrome involves trisomy 21 (an autosomal chromosome), and Klinefelter syndrome is associated with the XXY genotype.

Conclude that an individual with the XXY genotype would have Klinefelter syndrome, characterized by male physical traits and some degree of infertility.