In the yawncat a rare hypothetical animal the dominant allel

In the yawncat (a rare hypothetical animal), the dominant allele R causes solid tail color, and the recessive allele r results in white spots on a colored background. The black coat color allele B is dominant to the brown allele b, but these genes can only be expressed it the animal has an mm genotype at a third gene locus. Animals that are M_ are yellow regardless of which allele from the B locus is present. A mating between a solid yellow-tailed male yawncat and a solid brown-tailed female yawncat produces 16 offspring with the following tail phenotypes: six solid yellow, two spotted yellow, three solid black, one spotted black, three solid brown, and one spotted brown. What is the most likely genotype of the female parent? mm bb rr Mm bb rr mm Bb rr mm bb Rr mm Bb Rr

Solution

The correct answer is: d.mm bb Rr

Explanation: Let us consider the M locus first. The male is M_. and female is not yellow, so she will be mm. As all of the offspring are not yellow, the male must be Mm. Then let us consider the solid and spotted locus. As both the parents are solid, they should be R_. But as some offspring are found to be spotted, it means the male and female parents have Rr. Finally,let us consider the Band b locus.In this case,the brown female should be bb.But since some of the offspring are black while some are brown, it means that the male must Bb. So the genotype of female will be :

mm bb Rr