Genetics worksheet with answers

Two Rr parents are crossed. R gives black fur and is dominant over r, which gives white fur. Click the cell of the Punnett square for an offspring with white fur.

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

Two Bb parents are crossed. B gives yellow seeds and is dominant over b, which gives green seeds. Click the cell for an offspring that has yellow seeds and is homozygous.

1. 1b × b
2. 2b × B
3. 3B × b
4. 4B × 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, wrinkled seeds?

red-green colour blindness is X-linked recessive (allele b). A carrier mother, X^BX^b, has children with an unaffected father, X^BY. The mother's gametes run down the side. Click the cell for an unaffected son.

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

In a population of 1000 in Hardy–Weinberg equilibrium, 9% 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 2500 show a recessive trait. How many individuals N are expected to be homozygous dominant?