Genetics worksheet with answers

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

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

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?

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 unaffected son.

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 short, round seeds?

A recessive condition affects 1 in 400 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 10000 show a recessive trait. How many individuals N are expected to be homozygous dominant?