When roan cattle are mated, 25% of the offspring are red 50% are roan and 25% w e upon
examination, it can be seen that the coat of a roan cow consists of both red and white hans by what
this trait controlled?
A Multiple alleles
B Co-dominant alleles
C. Incomplete dominance genes
D. Dominant inheritance

B Co-dominant alleles

Explanation: The coat of a roan cow consists of both red and white because the two alleles are codominant. Codominance occurs when two alleles outwardly express themselves equally. In codominance, neither of the allele is completely dominant rather they are equally dominant. None is able to mask the effect of the other. The two alleles express themselves equally in the phenotype of the organism. This means that in a roan cow, the allele for white fur is dominant and the allele for red fur is equally dominant, thus they manifested equally as a mixture of both red and white furs.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).