Which type of dominance results in a phenotype that is a blend of the two alleles?

Incomplete dominance is characterized by a situation where the phenotype of the heterozygote is an intermediate blend of the phenotypes of the two homozygotes. In this case, when two different alleles are present, neither allele is fully dominant over the other, leading to a new phenotype that represents a mixing of the traits. For example, if one allele contributes to red flower color and the other to white flower color, the offspring may display a pink coloration rather than exhibiting either red or white fully.

This blending effect distinguishes incomplete dominance from co-dominance, where both alleles are expressed equally and individually, rather than mixing. Dominant and recessive inheritance focus on the relationship between dominant and recessive alleles, where one can mask the expression of another, but do not result in a blended phenotype in the manner described by incomplete dominance. Thus, the correct classification of this genetic interaction is incomplete dominance, as it is the one that leads to a phenotype that is a blend of the two alleles.