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 Tt parents are crossed. T gives yellow seeds and is dominant over t, which gives green seeds. Click the cell for an offspring that has yellow seeds and is homozygous.

1. 1t × t
2. 2t × T
3. 3T × t
4. 4T × T

haemophilia is X-linked recessive (allele h). A carrier mother, X^HX^h, has children with an affected 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

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, wrinkled seeds?

In a population of 1000 in Hardy–Weinberg equilibrium, 1 in 10000 show a recessive trait. How many individuals N are expected to be homozygous dominant?

In a population of 2000 in Hardy–Weinberg equilibrium, 1 in 10000 show a recessive trait. How many individuals N are expected to be homozygous dominant?