If a trait that is expressed in the phenotype is heterozygous and discrete,what do we then know for sure about that trait?
A) It is recessive.
B) It is dominant.
C) It is codominant.
D) It is polygenic.

Question

Quizplus · Accepted Answer

If a heterozygous trait is expressed, it must be dominant. This is because a recessive trait would only be expressed if it was present in two copies (i.e. homozygous recessive). Codominant traits involve both alleles being expressed equally in the phenotype, and polygenic traits involve multiple genes contributing to a single phenotype. Therefore, neither C nor D would be applicable for a heterozygous and discrete trait.

If a Trait That Is Expressed in the Phenotype Is