Genetic Crosses that Involve 2 Traits -- KEY

In rabbits, grey hair is dominant to white hair. Also in rabbits, black eyes are dominant to red eyes.

GG = gray hair Gg = gray hair gg = white hair

BB = black eyes Bb = black eyes bb = red eyes

1. What are the phenotypes (descriptions) of rabbits that have the following genotypes:

Ggbb ___Gray hair, red eyes___ ggBB _____white hair, black eyes__________

ggbb ___white hair, red eyes_______ GgBb ___gray hair, black eyes__________

2. A male rabbit with the genotype GGbb is crossed with a female rabbit with the genotype ggBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring.

How many out of 16 have grey fur and black eyes? ___8__ How many out of 16 have grey fur and red eyes? ___8_____ How many out of 16 have white fur and black eyes? __0____ How many out of 16 have white fur and red eyes? __0____

3. A male rabbit with the genotype GgBb is crossed with a female rabbit with the genotype GgBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring.

How many out of 16 have grey fur and black eyes? 9 How many out of 16 have grey fur and red eyes? 3 How many out of 16 have white fur and black eyes? 3 How many out of 16 have white fur and red eyes? 1

4. Show the cross between a ggBb and a GGBb. You'll have to set the square up yourself!

all will have gray hair gg x GG

3/4 black eyes, 1/4 red eyes