If G=yellow and g=green peas, and at a separate gene P=purple and p=white flowers, what proportion of your offspring will be yellow and white if you cross a Ggpp with a ggPp?

1/4

Explanation:

Given the genotype of parent plants: Ggpp and ggPp. The parent plant with Ggpp genotype will form two types of gametes in 1:1 ratio = Gp and gp.

The parent plant with genotype ggPp would form two types of gametes in 1:1 ratio = gP and gp. The random fusion of these gametes from two parents would obtain progeny in the following phenotype ratio=

1/4 yellow purple: 1/4 yellow white: 1/4 green purple: 1/4 green white

Therefore, 1/4 of the total progeny would be "yellow and white".