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

6. Chromosomal Variation

Chromosomal Mutations: Aneuploidy

Genetics

6. Chromosomal Variation

Chromosomal Mutations: Aneuploidy

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Multiple Choice

Which of the following processes will most likely produce a human zygote with 45 chromosomes?

Duplication of a segment within chromosome 18

Crossing over between homologous chromosomes during prophase I

A point mutation in a single gene on chromosome 21

Nondisjunction during meiosis leading to gamete formation with one missing chromosome

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Verified step by step guidance

Understand that a normal human zygote has 46 chromosomes, 23 from each parent, so any deviation from this number indicates an abnormality in chromosome number.

Recognize that duplication of a segment within chromosome 18 changes the structure of a chromosome but does not change the total chromosome count, so it won't produce a zygote with 45 chromosomes.

Know that crossing over during prophase I of meiosis involves exchange of genetic material between homologous chromosomes but does not alter the total number of chromosomes.

Realize that a point mutation affects only a single gene and does not impact chromosome number.

Identify that nondisjunction during meiosis can cause gametes to have an abnormal number of chromosomes, such as missing one chromosome, and when fertilization occurs, the resulting zygote will have 45 chromosomes instead of 46.