Genetics worksheet with answers

Two Rr parents are crossed. R gives yellow seeds and is dominant over r, which gives green seeds. Click the cell for an offspring that has yellow seeds and is homozygous.

1. 1r × r
2. 2r × R
3. 3R × r
4. 4R × R

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?

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?

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an affected father, X^hY. The mother's gametes run down the side. Click the cell for a carrier daughter.

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

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