Question

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.

Answer 1

The key to recognizing polygenic inheritance is that the trait demonstrates continuous variation within the population, indicating the involvement of multiple genes.

Step-by-step explanation:

The key to the recognition of a trait whose expression is determined by the effects of two or more genes (polygenic inheritance) is D) The trait varies along a continuum in the population. Unlike Mendelian inheritance, where traits are defined by a single gene pair and exhibit a clear dominant-recessive pattern, polygenic traits involve multiple genes contributing to a single phenotype. Traits that display continuous variation, such as height, skin color, and weight, are typically polygenic. These traits do not exhibit distinct categories but rather a range of phenotypes, influenced by both genetic and environmental factors.