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 is heterozygous (Aa)?

Two Aa parents are crossed. A gives yellow seeds and is dominant over a, which gives green seeds. Click the cell of the Punnett square for an offspring with green seeds.

1. 1a × A
2. 2a × a
3. 3A × A
4. 4A × a

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

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 a carrier daughter.

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

A recessive condition affects 1 in 2500 of a population in Hardy–Weinberg equilibrium. What fraction f of the population are carriers (heterozygous)?

In a population of 10000 in Hardy–Weinberg equilibrium, 1 in 400 show a recessive trait. How many individuals N are expected to be homozygous dominant?