What is a characteristic controlled by two or more genes called?

A characteristic controlled by two or more genes is called polygenic. In genetics, traits that are influenced by multiple genes tend to show a continuous range of phenotypic expression, which can lead to variations that are more complex than traits controlled by a single gene. Typical examples of polygenic traits include height, skin color, and weight in humans, where several genes contribute to the final expression of these traits.

In contrast, pleiotropic traits are those where a single gene affects multiple characteristics, which is not the focus of the question. Monogenic traits are determined by a single gene, and recessive relates to a specific mode of inheritance where a trait only manifests if two copies of the recessive allele are present. Therefore, understanding that polygenic traits involve multiple genes working together for expression is key to grasping this concept in genetics.