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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

6. Chromosomal Variation

Chromosomal Mutations: Aberrant Euploidy

Genetics

6. Chromosomal Variation

Chromosomal Mutations: Aberrant Euploidy

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Multiple Choice

Which of the following diseases is caused by a chromosomal abnormality present before birth?

Down syndrome

Huntington's disease

Cystic fibrosis

Sickle cell anemia

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Verified step by step guidance

Understand that chromosomal abnormalities involve changes in the number or structure of chromosomes, which are present from conception and affect many genes at once.

Recognize that Down syndrome is caused by trisomy 21, meaning there is an extra copy of chromosome 21, which is a chromosomal abnormality present before birth.

Know that Huntington's disease, cystic fibrosis, and sickle cell anemia are caused by mutations in specific genes rather than whole chromosome abnormalities.

Recall that Huntington's disease is caused by a mutation in the HTT gene, cystic fibrosis by mutations in the CFTR gene, and sickle cell anemia by a mutation in the HBB gene.

Conclude that among the options, only Down syndrome is caused by a chromosomal abnormality present before birth.