comb shape in chickens provides an interesting study in gene interactions. you cross two chickens with walnut combs. YOu obtain the following offspring in the indicated frequencies 9/16 walnut, 3/16 rose, 316 pea and 1/16 single. You cross two singles and you get 100% single offspring. You cross a rose with a pea, and you see 100% walnut. Explain how comb shape is inherited, the genotypes for the four phenotypes and how the cross of a rose comb with a pea comb results in 100% walnut.