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 Aa parents are crossed. A gives round seeds and is dominant over a, which gives wrinkled seeds. Click the cell of the Punnett square for an offspring with wrinkled seeds.

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

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 affected son.

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

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 affected son.

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

A recessive condition affects 16% of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

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

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