What distinguishes quantitative traits from polygenic traits?

The correct choice highlights that quantitative traits are characterized by their variation in amount rather than type. Quantitative traits, such as height or weight, display a continuous range of variations within a population. This means that individuals within a species can exhibit traits that vary in degree, measured on a scale — for example, a person can be 5 feet, 5.5 feet, or 6 feet tall, demonstrating a measurable variation in height.

In contrast, polygenic traits, while also influenced by multiple genes, focus more on how those multiple genes contribute to the continuous variation seen in quantitative traits. Thus, the emphasis of quantitative traits being about the extent or degree of a trait differentiates them from simply being termed polygenic, which describes the genetic basis of the trait rather than its variation.

The other options contain inaccuracies regarding the relationship between quantitative traits and polygenic traits. Quantitative traits do not center on variation in type as it pertains to categories, but rather on the expression of different degrees of a trait. Additionally, although polygenic traits can be influenced by environmental factors, they are not solely determined by them or epigenetics, which do not primarily distinguish between quantitative and polygenic characteristics.