Genetics worksheet with answers

Two Rr parents are crossed. R gives round seeds and is dominant over r, which gives wrinkled seeds. Click the cell of the Punnett square for an offspring with wrinkled seeds.

1. 1r × r
2. 2r × R
3. 3R × r
4. 4R × R

Two Aa parents are crossed. A gives tall plants and is dominant over a, which gives short plants. Click the cell of the Punnett square for an offspring with short plants.

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 short, round seeds?

red-green colour blindness is X-linked recessive (allele b). A carrier mother, X^BX^b, has children with an affected father, X^bY. The mother's gametes run down the side. Click the cell for an unaffected 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 purple flowers (dominant) or white flowers; gene B gives black fur (dominant) or white fur. Click the one cell for an offspring that is homozygous for purple flowers and shows 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

A recessive condition affects 1 in 1600 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?