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 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

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 a carrier daughter.

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

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 affected son.

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

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

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

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 homozygous for black fur and for yellow 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