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

2. Mendel's Laws of Inheritance

Probability and Genetics

Genetics

2. Mendel's Laws of Inheritance

Probability and Genetics

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Multiple Choice

In a family where both parents are heterozygous carriers for cystic fibrosis (genotype Ff), what is the probability that their daughter Irene is a carrier (heterozygous) for the disease? Express your answer as a percentage.

25%

50%

100%

75%

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Verified step by step guidance

Identify the genotypes of the parents. Both parents are heterozygous carriers for cystic fibrosis, so their genotypes are Ff and Ff.

Set up a Punnett square to determine the possible genotypes of their offspring. The alleles from each parent (F and f) combine to form the following genotypes: FF, Ff, fF, and ff.

List the possible genotypes of the children: FF (homozygous dominant, not a carrier), Ff (heterozygous carrier), fF (heterozygous carrier), and ff (homozygous recessive, affected by cystic fibrosis). Note that Ff and fF are functionally the same genotype (heterozygous carrier).

Calculate the probability of each genotype by counting the number of occurrences in the Punnett square. There is 1 FF, 2 Ff (or fF), and 1 ff out of 4 total possibilities.

Determine the probability that Irene is a carrier (heterozygous) by dividing the number of heterozygous genotypes by the total number of genotypes: $\frac{2}{4} = 0.5$, which corresponds to 50%.