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 tall plants and is dominant over a, which gives short plants. Click the cell for an offspring that has tall plants and is homozygous.

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

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 black fur (dominant) or white fur; gene B gives tall plants (dominant) or short plants. Click the one cell for an offspring that is shows both white fur and short 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

Two AaBb parents are crossed. Gene A gives tall plants (dominant) or short plants; gene B gives purple flowers (dominant) or white flowers. Click the one cell for an offspring that is shows both short plants and white flowers.

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