I need help solving this... Dont exactly know how to solve/set this up.

Question

1. A geneticist puts a female mouse from a line that breeds true for wild-type eye and body color with a male mouse from a pure line having apricot eyes (determined by allele a) and gray coat (determined by allele g). The mice mate and produce an F1 that is all wild-type. The F1 mice intermate and produce an F2 of the following composition: 

Females all wild-type

Males wild-type 45%

Apricot, gray 45%

Gray 5%

Apricot 5%

Give the genotypes of the parents, and of both sexes of the F1 and F2.

Answer 1

"Wild type" means the most common allele in nature. In this example we are told that the female mouse has wild-type eye color and body color. The male has apricot eyes (a) and gray coat (g). We are also told that the male is from a pure line.

In questions like this, uppercase letters like "A" represent a dominant allele while lowercase letters like "a" represent a recessive allele. We were told that apricot eye color is represented using a and gray coat color using g. From this, it follows that the wild type eye color is represented using A and wild type coat color is G.

Both the male and the female are from pure lines. The female parent, who is wild type, therefore has the genotype AAGG. The male parent has the genotype aagg.

When the parents mate, the genotype of all the mice in the F1 generation will be the same, AaGg. This is because, for eye color, the female parent can only give the "A" allele while the male parent can only give the "a" allele. For coat color, the female parent can only give the "G" allele while the male parent can only give the "g" allele. Therefore, each offspring in the F1 generation will have one A allele from the mother, one a allele from the father, one G allele from the mother, and one g allele from the father.

In the F2 generation, we will be crossing two F1s, AaGg x AaGg and there will be many different genotypes. One-sixteenth of the offspring will have AAGG, one-eighth will have have AAGg, one-eighth will have AaGG, one-fourth will have AaGg, one-sixteenth will have AAgg, one-sixteenth will have aaGG, one-eighth will have Aagg, one-eighth will have aaGg, and one-sixteenth will have aagg. This is complicated to explain but if you Google "dihybrid cross" you can easily find Punnett squares showing identical crosses with different traits.