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 purple flowers?

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an unaffected father, X^HY. The mother's gametes run down the side. Click the cell for a carrier daughter.

1. 1X^H × Y
2. 2X^H × X^H
3. 3X^h × Y
4. 4X^h × X^H

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 short, wrinkled seeds?

Two AaBb parents are crossed. Gene A gives yellow seeds (dominant) or green seeds; gene B gives purple flowers (dominant) or white flowers. Click the one cell for an offspring that is shows green seeds and is homozygous for purple flowers.

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)?