In Shorthorn cattle, coat color may be red, white, or roan. Roan is an intermediate phenotype expressed as a mixture of red and white hairs. For this problem, use "A" to indicate the allele that produces red hair, and "a" to indicate the allele that produces white hair. The following phenotypic data are obtained from various crosses: Cross 1: red × red → all red Cross 2: white × white → all white Cross 3: red × white → all roan Cross 4: roan × roan → 1/4 red: 1/2 roan: 1/4 How is coat color inherited?
by incomplete dominance
by recessive epistasis
by dominant epistasis
by multiple alleles
What are the genotypes of parents in cross 1?
1. AA
2. Aa
3. aa