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 has purple flowers?

Two Bb parents are crossed. B gives purple flowers and is dominant over b, which gives white flowers. Click the cell for an offspring that has purple flowers and is homozygous.

1. 1b × b
2. 2b × B
3. 3B × b
4. 4B × B

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

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, round seeds?

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

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