Table of contents

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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

Which of the following individuals has 46 chromosomes in their somatic cells?

A person with Turner syndrome

A person with Down syndrome

A typical human

A person with Klinefelter syndrome

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Verified step by step guidance

Step 1: Understand that somatic cells are all body cells except the gametes, and a typical human somatic cell contains 46 chromosomes arranged in 23 pairs.

Step 2: Recall that Turner syndrome individuals have a chromosomal composition of 45 chromosomes (45,X), meaning they have only one X chromosome and are missing one sex chromosome.

Step 3: Recognize that individuals with Down syndrome have an extra chromosome 21, resulting in 47 chromosomes (trisomy 21) in their somatic cells.

Step 4: Know that Klinefelter syndrome individuals have an extra X chromosome, typically 47 chromosomes (47,XXY) in their somatic cells.

Step 5: Conclude that only a typical human has exactly 46 chromosomes in their somatic cells, while the others have either fewer or more chromosomes due to their syndromes.