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 for an offspring that has tall plants and is homozygous.

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

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

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

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?

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 son.

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

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

In a population of 2000 in Hardy–Weinberg equilibrium, 1 in 400 show a recessive trait. How many individuals N are expected to be homozygous dominant?