Question

How do phenotypes appear in codominance?

Answer 1

In genetics, the dominant genes are those which are always expressed if they are present in an organism. In codominance, the two different traits are expressed alongside each other.

Complete answer:
Codominance occurs when both the two heterozygous alleles are fully expressed. Neither of the allele can dominate, hence they both show up, but they do not blend. Both the alleles are expressed separately in different parts of an organism. Both of the traits appear, instead of one trait being dominant over the other.
In this inheritance pattern, the phenotypes of both the parents are combined into a third, unique phenotype. A phenotype is a way to use traits to describe the genes. Codominance results in the two phenotypes being expressed in different parts of an animal.
One of the examples of codominance is blood group AB. In the blood types A, B, AB and O, blood type A can be AA or AO, B blood type can be BB or BO, AB is AB and O blood type is always OO. The AB blood type shows codominance as the genotype (AB) is the same as its phenotype (AB). OO is not codominant as O is recessive to the other types.

Note: Rhododendrons and some other flowers also exhibit codominance. In the case of rhododendrons, the crossing of a white and red flower may yield a flower that has both white and red patches. Many flowers show similar patterns of the codominance, where both of the parental flower colors show up in various parts of the plant.