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

Consider an organism with a diploid chromosome number of 2n = 20. Which of the following represents an example of aneuploidy in this organism?

A cell with 10 chromosomes (haploid)

A cell with 21 chromosomes (trisomy)

A cell with 40 chromosomes (tetraploid)

A cell with 20 chromosomes (normal diploid)

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Verified step by step guidance

Step 1: Understand the terms involved. The diploid number (2n) is the total number of chromosomes in a normal somatic cell, which is 20 in this organism. Haploid (n) means half the diploid number, so 10 chromosomes in this case.

Step 2: Define aneuploidy. Aneuploidy refers to a chromosome number that is not an exact multiple of the haploid set, usually due to the gain or loss of one or a few chromosomes, such as trisomy (one extra chromosome) or monosomy (one missing chromosome).

Step 3: Analyze each option in terms of chromosome number relative to the normal diploid number (20). For example, 10 chromosomes is haploid, 20 is normal diploid, 40 is tetraploid (double diploid), and 21 is one extra chromosome compared to diploid.

Step 4: Identify which chromosome number represents aneuploidy by checking if it deviates from exact multiples of the haploid number (10) by a small amount (usually one chromosome). Trisomy (21 chromosomes) fits this definition.

Step 5: Conclude that the example of aneuploidy is the cell with 21 chromosomes (trisomy), as it has one extra chromosome beyond the normal diploid number.