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 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

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

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 a carrier daughter.

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

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