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 Aa parents are crossed. A gives black fur and is dominant over a, which gives white fur. Click the cell for an offspring that has black fur and is homozygous.

1. 1a × A
2. 2a × a
3. 3A × A
4. 4A × a

red-green colour blindness is X-linked recessive (allele b). A carrier mother, X^BX^b, has children with an affected father, X^bY. The mother's gametes run down the side. Click the cell for a carrier daughter.

1. 1X^b × X^b
2. 2X^b × Y
3. 3X^B × X^b
4. 4X^B × 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, round seeds?

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 homozygous for round seeds and shows green 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 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