Genetics worksheet with answers

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

1. 1t × t
2. 2t × T
3. 3T × t
4. 4T × T

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 × 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?

A recessive condition affects 1 in 10000 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

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