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)?

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 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

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?

In a population of 5000 in Hardy–Weinberg equilibrium, 1 in 2500 show a recessive trait. How many individuals N are expected to be homozygous dominant?

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