What does the term 'codominance' refer to in genetics?

Codominance in genetics describes a situation where both alleles for a trait are fully expressed in a heterozygous individual. This means that the characteristics associated with both alleles are observable in the phenotype without blending them into an intermediate form. For example, in certain breeds of cattle, a cross between a red cow and a white cow can produce offspring with both red and white patches, rather than a solid color. This distinct expression of both alleles allows for a clear demonstration of each trait, highlighting the unique nature of codominance.

Options describing dominance or recessiveness do not apply as they do not encompass the essence of codominance, which relies on the equal expression of both traits rather than the overshadowing of one by another. Similarly, incomplete dominance refers to a blending of traits rather than their individual expression, further distinguishing it from codominance.