Traits controlled by two or more genes are called?

• A. Polygenic traits
• B. Monogenic traits
• C. Epistasis traits
• D. Pleiotropic traits

Answer: (A)

Traits that are shaped by several genes show continuous, gradual variation because many genes each contribute a small amount to the final phenotype. This pattern is called polygenic traits. Height and skin color are classic examples, where a range of phenotypes emerges rather than neat, separate categories. Environmental factors can also influence the final outcome, adding even more variation. In contrast, a trait controlled by a single gene tends to produce distinct, discrete forms. Pleiotropy means one gene impacts multiple, different traits rather than changing how many genes govern a single trait. Epistasis involves interactions between genes that modify expression, which can influence polygenic traits but doesn’t define the trait itself.