Genetics worksheet with answers

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

1. 1t × T
2. 2t × t
3. 3T × T
4. 4T × t

Two Bb parents are crossed. B gives black fur and is dominant over b, which gives white fur. Click the cell of the Punnett square for an offspring with white fur.

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

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 unaffected son.

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

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 short, wrinkled seeds?

A recessive condition affects 9% 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 purple flowers (dominant) or white flowers. Click the one cell for an offspring that is homozygous for round seeds and for purple flowers.

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