What is the key to the recognition of a trait whose expression is determined by the effects of two or more genes (polygenic inheritance)?
A) A mating between a homozygous and a heterozygous individual produces more than the expected number of offspring expressing the dominant trait.
B) All of the alleles of the gene for that trait are equally expressed.
C) Pleiotropy occurs.
D) The trait varies along a continuum in the population.

Question

Quizplus · Accepted Answer

Polygenic inheritance results in the trait varying along a continuum in the population, rather than being a discrete trait with only two possible expressions. This is due to the combined effects of multiple genes, each contributing to the overall expression of the trait. Therefore, the key to recognizing a trait that is determined by the effects of two or more genes is to observe variation in the trait within the population. A and B are not correct because they do not reflect the variability that is characteristic of polygenic inheritance. Pleiotropy is a phenomenon in which a single gene affects multiple traits, so C is also incorrect in this context.

What Is the Key to the Recognition of a Trait