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 Bb parents are crossed. B gives round seeds and is dominant over b, which gives wrinkled seeds. Click the cell for an offspring that has round seeds and is homozygous.

1. 1b × B
2. 2b × b
3. 3B × B
4. 4B × b

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?

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an affected father, X^hY. The mother's gametes run down the side. Click the cell for an affected son.

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

In a population of 1000 in Hardy–Weinberg equilibrium, 1 in 2500 show a recessive trait. How many individuals N are expected to be homozygous dominant?

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