Final answer:
When a roan bull and a roan cow are mated, the expected genotype of their offspring is a mix of three possible genotypes: RR, Rr, and rr.
Step-by-step explanation:
When a roan bull and a roan cow are mated, the expected genotype of their offspring is a mix of three possible genotypes: RR, Rr, and rr. In this case, 'R' represents the dominant allele for the roan coat color, and 'r' represents the recessive allele for the solid coat color.
The genotypes of the offspring can be predicted using a punnett square. For example, crossing two RR roan bulls would result in all RR offspring.
Crossing an RR roan bull with an rr solid cow would result in all Rr offspring. And crossing two rr solid cows would result in all rr offspring. Therefore, the expected genotypes of the offspring from a roan bull and a roan cow mating are a mix of RR, Rr, and rr genotypes.