Genetics worksheet with answers

In pea plants, purple flowers (A) are dominant over white (a). A plant with genotype AA is crossed with a plant with genotype Aa. What is the probability P that an offspring is heterozygous (Aa)?

In pea plants, purple flowers (A) are dominant over white (a). A plant with genotype Aa is crossed with a plant with genotype Aa. What is the probability P that an offspring has white flowers?

Tall (A) is dominant over short (a), and round seeds (B) over wrinkled (b). The genes are on different chromosomes. For the cross AaBb × AaBb, what is the probability P that an offspring is tall, wrinkled seeds?

Duchenne muscular dystrophy is X-linked recessive (allele d). A carrier mother, X^DX^d, has children with an unaffected father, X^DY. The mother's gametes run down the side. Click the cell for an unaffected son.

1. 1X^d × X^D
2. 2X^d × Y
3. 3X^D × X^D
4. 4X^D × Y

Two AaBb parents are crossed. Gene A gives tall plants (dominant) or short plants; gene B gives yellow seeds (dominant) or green seeds. Click the one cell for an offspring that is shows both short plants and green seeds.

1. 1ab × ab
2. 2ab × AB
3. 3ab × aB
4. 4ab × Ab
5. 5AB × ab
6. 6AB × AB
7. 7AB × aB
8. 8AB × Ab
9. 9Ab × ab
10. 10Ab × AB
11. 11Ab × aB
12. 12Ab × Ab
13. 13aB × ab
14. 14aB × AB
15. 15aB × aB
16. 16aB × Ab

A recessive condition affects 4% of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?