Question

A cross was made between a white male dog and two different black females. the first female gave birth to eight black pups, and the second female gave birth to four white and three black pups. what are the likely genotypes of the male parent and the two female parents? explain whether you are uncertain about any of the genotypes.

Answer 1

In this case, the black body colour is the dominant one. The white dog is  homozygous recessive.

As the cross between the black female 2 and the white male results in all black pups. This means that the all the offsprings are heterozygotes and the Female 1 is homozygous recessive having a BB phenotype (where B codes for dominant allele).

As the cross between the black female and the white male results in four white and three black pups. This means that the all the black offsprings are heterozygotes, and the white ones are homozygous recessive and the Female 2 have a dominant and 1 recessive gene, and is a hetrozygotezygous recessive having a Bb phenotype (where B codes for dominant allele and b codes for recessive allele).