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

Overview of interacting Genes

Genetics

3. Extensions to Mendelian Inheritance

Overview of interacting Genes

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Multiple Choice

Which mother is at greatest risk of having a child with a chromosomal abnormality?

A 25-year-old woman

A 19-year-old woman

A 30-year-old woman

A 42-year-old woman

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Verified step by step guidance

Understand that the risk of chromosomal abnormalities in offspring is related to the age of the mother, with risk increasing as maternal age increases.

Recall that common chromosomal abnormalities, such as Down syndrome (trisomy 21), are more frequent in children born to older mothers due to nondisjunction events during meiosis.

Recognize that the problem lists ages 19, 25, 30, and 42 years, and you need to compare the relative risk of chromosomal abnormalities associated with each age.

Know that the risk is lowest in younger mothers (teens and twenties), increases moderately in the early thirties, and rises significantly after age 35, becoming highest in mothers aged 40 and above.

Conclude that among the given options, the 42-year-old woman is at the greatest risk of having a child with a chromosomal abnormality because risk increases with maternal age, especially beyond 35 years.