Genetics worksheet with answers

Two Aa parents are crossed. A gives black fur and is dominant over a, which gives white fur. Click the cell of the Punnett square for an offspring with white fur.

1. 1A × A
2. 2A × a
3. 3a × A
4. 4a × a

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 an unaffected son.

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

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, round seeds?

Two AaBb parents are crossed. Gene A gives purple flowers (dominant) or white flowers; gene B gives yellow seeds (dominant) or green seeds. Click the one cell for an offspring that is homozygous for purple flowers and shows 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 9% of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?