What is the phenotypic ratio when crossing two walnut combed chickens?

The correct phenotypic ratio for the offspring of two walnut combed chickens reflects the inheritance of two different traits governed by two alleles. Walnut combs in chickens are controlled by two genes that exhibit a form of epistasis, which influences how the traits manifest in the phenotypes.

When two walnut-combed chickens are crossed, they display a typical dihybrid inheritance pattern. In this case, let's assume that the walnut comb trait is represented by two alleles that each have two forms - one being considered dominant over the other. When conducting a dihybrid cross of two organisms heterozygous for both traits, the resulting offspring will typically display a phenotypic ratio of 9:3:3:1. This ratio indicates that 9 parts will show the dominant phenotype for both traits, 3 parts will show the dominant phenotype for one trait and the recessive for the other, another 3 parts will show the opposite (dominant for the second trait and recessive for the first), and 1 part will show the recessive phenotype for both traits.

This understanding of inheritance patterns explains the presence of multiple traits being expressed simultaneously, resulting in the specified ratios. Thus, the phenotypic ratio of 9