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 black fur and is dominant over r, which gives white fur. Click the cell of the Punnett square for an offspring with white fur.

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

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 affected son.

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

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