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 has purple flowers?

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

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 unaffected father, X^HY. The mother's gametes run down the side. Click the cell for an unaffected son.

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

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

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

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