Genetics worksheet with answers

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

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

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

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

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 affected daughter.

1. 1X^B × Y
2. 2X^B × X^b
3. 3X^b × Y
4. 4X^b × X^b

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 tall, round seeds?

Two AaBb parents are crossed. Gene A gives purple flowers (dominant) or white flowers; gene B gives yellow seeds (dominant) or green seeds. Click the one cell for an offspring that is homozygous for purple flowers 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

In a population of 10000 in Hardy–Weinberg equilibrium, 16% show a recessive trait. How many individuals N are expected to be homozygous dominant?