Think about the problem of cone shape inheritance in chickens, where walnut, rose, pea, and single are observed as distinct phenotypes. Considering the following data, determine how comb shape is inherited and what genotypes are present in each cross:
Cross 1: single x single à all single
Cross 2: walnut x walnut à all walnut
Cross 3: rose x pea à all walnut
Cross 4: F1 x F1 of Cross 3
walnut x walnut à 93 walnut
28 rose
32 pea
10 single