What is polygenic inheritance?

Polygenic inheritance refers to the phenomenon where a single trait is controlled by multiple genes, each contributing to the phenotype in a cumulative or additive manner. This results in a wide range of possible phenotypes, particularly for traits that display continuous variation, such as height, skin color, or intelligence.

In polygenic inheritance, each gene may have a small effect, but collectively, they determine the expression of the trait. This can lead to complex patterns of inheritance that do not follow simple Mendelian ratios, since traits influenced by multiple genes can exhibit a bell-shaped distribution in a population.

The other options do not accurately define polygenic inheritance. A trait controlled by a single gene describes monogenic inheritance, which is distinctly different. A trait influenced solely by environmental factors doesn't involve genetic contribution, contradicting the essence of inheritance. Lastly, stating that a trait is not passed on to offspring implies a lack of genetic transmission, which is not characteristic of any form of inheritance. Understanding polygenic inheritance is critical for studying complex traits and the genetic basis of variation in populations.