Genetics worksheet with answers

Two Rr parents are crossed. R gives yellow seeds and is dominant over r, which gives green seeds. Click the cell for an offspring that has yellow seeds and is homozygous.

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

Two Tt parents are crossed. T gives purple flowers and is dominant over t, which gives white flowers. Click the cell for an offspring that has purple flowers and is homozygous.

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

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?

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

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

In a population of 5000 in Hardy–Weinberg equilibrium, 1% 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 yellow seeds (dominant) or green seeds. Click the one cell for an offspring that is shows both white fur and green 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