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

A human egg with 22 chromosomes (missing a sex chromosome) that is fertilized by a normal sperm will result in which of the following zygotic conditions?

Normal female (XX)

Trisomy 21 (Down syndrome)

Monosomy X (Turner syndrome)

Klinefelter syndrome (XXY)

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Verified step by step guidance

Step 1: Understand the normal chromosome numbers in human gametes. A typical human egg contains 23 chromosomes, including one sex chromosome (X), and a normal sperm also contains 23 chromosomes, including either an X or a Y sex chromosome.

Step 2: Analyze the given egg's chromosome content. The egg has 22 chromosomes and is missing a sex chromosome, meaning it has one fewer chromosome than normal and lacks the X or Y chromosome.

Step 3: Determine the chromosome number in the resulting zygote after fertilization. Since the sperm is normal with 23 chromosomes (including a sex chromosome), the zygote will have 22 (from egg) + 23 (from sperm) = 45 chromosomes total.

Step 4: Identify the sex chromosome composition of the zygote. Because the egg lacks a sex chromosome, the zygote will have only one sex chromosome from the sperm (either X or Y), resulting in a single sex chromosome condition.

Step 5: Connect the chromosome number and sex chromosome composition to known syndromes. A zygote with 45 chromosomes and a single X chromosome (45,X) corresponds to Monosomy X, also known as Turner syndrome.