A brown mouse is mated to a white mouse and all of their off

A brown mouse is mated to a white mouse and all of their offspring are brown. a. Give a name to the gene responsible for this trait, and assign symbols for the possible alleles. Which allele is dominant? b. What are the genotypes of the mice that were crossed? c. If two of the F_1 brown offspring were mated together, what percentage of the F_2 mice would be brown?

Solution

Answer:

(a)

Fur color is the trait

alleles:

Brown= B

White=b

(b)

Parental genotypes: BB(Brown mouse) x bb (White mouse)

F1= Bb (all brown)

(c)

If F1 x F1

Bb x Bb

= BB (brown), Bb(brown), Bb(brown), bb(white)

3:1 ratio

75% mice are brown in color