Genetics worksheet with answers

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

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)?

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an unaffected father, X^HY. The mother's gametes run down the side. Click the cell for an affected son.

1. 1X^H × X^H
2. 2X^H × Y
3. 3X^h × X^H
4. 4X^h × Y

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an unaffected father, X^HY. The mother's gametes run down the side. Click the cell for an unaffected son.

1. 1X^h × X^H
2. 2X^h × Y
3. 3X^H × X^H
4. 4X^H × Y

A recessive condition affects 4% of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

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