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 white flowers?

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, round seeds?

red-green colour blindness is X-linked recessive (allele b). A carrier mother, X^BX^b, has children with an unaffected father, X^BY. The mother's gametes run down the side. Click the cell for an affected son.

1. 1X^B × Y
2. 2X^B × X^B
3. 3X^b × Y
4. 4X^b × X^B

Two AaBb parents are crossed. Gene A gives round seeds (dominant) or wrinkled seeds; gene B gives tall plants (dominant) or short plants. Click the one cell for an offspring that is shows both wrinkled seeds and short 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 in 2500 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?