Final answer:
In incomplete dominance and codominance genetic scenarios, the heterozygote exhibits a phenotype that is notably different from either of the homozygous conditions. Incomplete dominance results in an intermediate trait, while codominance displays both traits simultaneously.
Step-by-step explanation:
In both codominance and incomplete dominance, the heterozygote shows a phenotype that is distinct from either homozygote.
With incomplete dominance, the heterozygote displays a phenotype that is intermediate to both homozygous forms. For example, if a red flowered plant is crossed with a white flowered plant, the offspring may have pink flowers, indicative of incomplete dominance. In contrast, codominance occurs when both alleles for a trait are simultaneously and equally expressed in the heterozygote. An example is the human MN blood group, where both M and N antigens can be present on the surface of red blood cells, resulting in a phenotype that exhibits both characteristics.