Genetics worksheet with answers

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

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 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?

Duchenne muscular dystrophy is X-linked recessive (allele d). A carrier mother, X^DX^d, has children with an affected 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

A recessive condition affects 1 in 2500 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

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