What type of inheritance involves multiple genes influencing a single trait?

Polygenic inheritance describes a scenario where multiple genes contribute to the expression of a single trait. Each of these genes can have several alleles, and their combined effects result in a continuous range of phenotypes. This is commonly observed in traits such as height, skin color, and eye color in humans, where the variation is not due to a single gene but rather the additive effects of many genes working together.

In contrast to other options, co-dominance refers to a situation where two different alleles at the same locus are both expressed, leading to offspring with a phenotype that displays both parental traits simultaneously. Incomplete dominance involves a blending of traits, where the phenotype is a mix of the dominant and recessive traits rather than the distinct expression of both. Linked inheritance pertains to genes that are located close together on the same chromosome and tend to be inherited together, rather than influencing a single trait through multiple genes.

Therefore, the distinguishing characteristic of polygenic inheritance is the involvement of multiple genes that collectively determine one particular trait, providing a clear understanding of the genetic complexity behind such traits.