In swine,when a pure-breeding red is crossed to a pure-breeding white,the F₁ are all red.However,the F₂ shows 9/16 red,1/16 white,and 6/16 as a new color-sandy.A particular red individual (Parent 1)is crossed to a particular sandy individual (Parent 2),and the progeny is comprised of four sandy,three red,and one white piglets.What are the most likely genotypes of the two parents?

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The inheritance pattern suggests a dihybrid cross with epistasis, where the A allele is necessary for pigment production and the B allele determines the pigment color (red or sandy). The white phenotype likely results from the recessive bb genotype in the absence of dominant A. Since the cross produces all three phenotypes, both parents must contribute alleles for both traits, and the presence of a white offspring indicates that both parents must carry the recessive b allele. The sandy phenotype in the progeny suggests that at least one parent must be heterozygous at both loci (A/a;B/b), and the presence of red offspring indicates the other parent must also contribute the A allele and can contribute the b allele, making the most likely genotypes A/a;b/b and A/a;B/b.

In Swine,when a Pure-Breeding Red Is Crossed to a Pure-Breeding