In mice, the black allele (B) is dominant to the recessive white allele (b). Two black mice of unknown genotype are mated to each other, resulting in 6 black and 1 white . What is the genotype of the mother? Solution Answer: genotype of the mother = Bb Explanation: The only possible genotype for parents are P1: Bb (Black Mouse) X Bb (Black Mouse) F1: BB (Black), Bb(Black), Bb(black), bb(Black).