Genetics worksheet with answers

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

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 is heterozygous (Aa)?

Duchenne muscular dystrophy is X-linked recessive (allele d). A carrier mother, X^DX^d, has children with an unaffected father, X^DY. The mother's gametes run down the side. Click the cell for an unaffected son.

1. 1X^d × X^D
2. 2X^d × Y
3. 3X^D × X^D
4. 4X^D × Y

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?

In a population of 500 in Hardy–Weinberg equilibrium, 1 in 1600 show a recessive trait. How many individuals N are expected to be homozygous dominant?

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