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 white flowers?

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

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 unaffected son.

1. 1X^h × X^H
2. 2X^h × Y
3. 3X^H × X^H
4. 4X^H × Y

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, wrinkled seeds?

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

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