Question

Among Delta-back stripped fish, there are two genes that segregate independently of one another. Suppose the alleles at the first locus are A (dominant) and a (recessive) and the alleles at the second locus are B (dominant) and b recessive). If an AABB fish mates with an aabb fish, and their offspring are inter-crossed, the proportion of F2 fish that show a recessive phenotype at the first locus and a dominant phenotype at the second is:

Answer 1

4/16

Step-by-step explanation:

It is given that the alleles of the first locus = A dominant and recessive a

The allele of the second locus = B dominant and the recessive b.

Now if fish with AABB mates with the aabb fishes, then to tell the proportion of the F2 fish which shows either the dominant phenotype at the
`$\text{first locus}$` and also a recessive phenotype at the
`$\text{second locus}$`.

So for this, the recessive phenotype at the
`$\text{first locus}$` as well as the recessive phenotype at the
`$\text{second locus}$` is in the ratio of 4/16.