What does incomplete dominance refer to?

Incomplete dominance refers to a genetic scenario where one allele does not completely mask the effects of another allele, resulting in a phenotype that is a blend or intermediate of the two traits. In this case, when two alleles are present, instead of one being fully dominant and the other being fully recessive, both contribute to the phenotype in a way that creates a distinct, intermediate expression.

For example, in plants, if one allele codes for red flowers and another codes for white flowers, the offspring may exhibit pink flowers when each allele is expressed incompletely. This distinct phenotype reflects the influence of both alleles, illustrating how incomplete dominance operates within the framework of inheritance.

The other concepts, like complete dominance where one allele is fully dominant over another, and situations where both alleles are equally expressed, do not apply here because they do not capture the essence of incomplete dominance, which specifically involves a blending of traits rather than a complete or equal expression.