What is the term for a trait that is controlled by two or more genes and may also be influenced by environmental factors?

A trait that is controlled by two or more genes and can also be influenced by environmental factors is referred to as a polygenic trait. Polygenic traits exemplify the complexity of genetics, as these traits arise from the combined effects of multiple genes, each contributing a small amount to the overall phenotype. This interaction among various alleles leads to continuous variation in traits, such as height, skin color, and weight in humans, which cannot be attributed to a single genetic locus.

Environmental factors can further modify the expression of polygenic traits, demonstrating that genetics and environment often work together to shape an individual's characteristics. This is in contrast to monogenic traits, which are influenced by a single gene, and thus do not show the same level of complexity. Dominant traits refer to specific inheritance patterns where certain alleles mask the expression of others, and conditional traits are typically influenced by specific environmental conditions rather than multiple genes. Therefore, the concept of polygenic inheritance encapsulates the intricate relationship between multiple genes and environmental influences in determining traits.