Genetics worksheet with answers

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

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?

Duchenne muscular dystrophy is X-linked recessive (allele d). A carrier mother, X^DX^d, has children with an unaffected father, X^DY. The mother's gametes run down the side. Click the cell for a carrier daughter.

1. 1X^d × X^D
2. 2X^d × Y
3. 3X^D × X^D
4. 4X^D × 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?

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 round seeds (dominant) or wrinkled seeds; gene B gives black fur (dominant) or white fur. Click the one cell for an offspring that is shows both wrinkled seeds and 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