Genetics worksheet with answers

Two Bb parents are crossed. B gives tall plants and is dominant over b, which gives short plants. Click the cell of the Punnett square for an offspring with short plants.

1. 1B × b
2. 2B × B
3. 3b × b
4. 4b × B

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)?

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 a carrier daughter.

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 unaffected son.

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

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

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