In guinea pigs, the gene for production of melanin is epistatic to the gene for the deposition of melanin. The dominant allele Mcauses melanin to be produced; mm individuals cannot produce the pigment. The dominant allele B causes the deposition of a lot ofpigment and produces black guinea pig, whereas only a small amountof pigment is laid down in bb animals, producing a light browncolor. Without an M allele, no pigment is produced so the allele Bhas no effect and the guinea pig is white. A homozygous blackguinea pig is crossed with homozygous recessive white: MMBB x mmbb. Give the phenotypic ratio of the F1 and F2 generations.