Some traits are considered to be quantitative even though phenotypes are classified only as present or absent. Genetic diseases often fit this description. What is the term used to describe this type of trait?

A. polygenic trait

B. threshold trait

C. meristic trait

D. epistatic trait

E. environmental trait

The correct answer is option B. threshold trait.

Explanation:

Quantitative characteristics that are separately expressed in a limited (mostly two) number of physical character or phenotype but phenotypes are classified only as absent or present.

Usually these traits, their inheritance is determined by the environment and multiple genes. Genetics diseases such as the onset of diabetes are generally fit with this description of the threshold trait.

Thus, the correct answer is option B.