Question

Suppose two BbCc mice are crossed together. Assuming that the two genes assort independently, what are the expected phenotypes, and their ratios, in their offspring?

Answer 1

Answer:

4 types of phenotypes with phenotypic ratio 9:3:3:1 will be obtained.

Explanation:

The  Punnett square diagram for the cross between mice with genotype BbCc & BbCc  is attached.

It is clear from the diagram attached that the phenotypic ratio will be 9:3:3:1

• The following 9 genotypes will show dominant trait for both the characters i.e. characters represented by B & C genes.

        BBCC, BBCc, BbCC, BbCc, BBCc, BbCc, BbCC, BbCc, BbCc

• The following 3 genotypes will show dominant trait for one character represented by gene B and recessive trait for other character  represented by gene C.

       BBcc, Bbcc, Bbcc  

• The following 3 genotypes will show recessive trait for one character represented by gene B and dominant trait for other character  represented by gene C.

        bbCC, bbCc, bbCc  

• The following genotype is the only genotype which will show recessive trait for both the characters represented by gene B & C.

        bbcc