Question

Which of the following terms refers to a situation where a single phenotypic character is determined by the additive effects of two or more genes?

1) co-dominance
2) pleiotropy
3) incomplete dominance
4) polygenic inheritance

Answer 1

Polygenic inheritance describes a situation where multiple genes contribute to a single phenotypic trait, resulting in continuous variation across a range.

Step-by-step explanation:

The term that refers to a single phenotypic character determined by the additive effects of two or more genes is polygenic inheritance. This concept differs from co-dominance, where both alleles are simultaneously expressed, or incomplete dominance, where a blend of both alleles is expressed. Instead, polygenic inheritance involves multiple genes, each contributing to the phenotype, often resulting in a continuous range of variation, as seen in human skin color or height.