Genetics worksheet with answers

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

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 affected 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 tall, round seeds?

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

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

In a population of 5000 in Hardy–Weinberg equilibrium, 1 in 400 show a recessive trait. How many individuals N are expected to be homozygous dominant?