When Multiple Genes Contribute to the Expression of a Phenotype

Question

When multiple genes contribute to the expression of a phenotype they are called _____ .
A)concordant alleles
B)homozygous alleles
C)heterozygous alleles
D)nonadditive alleles
E)additive alleles

Accepted Answer

When multiple genes contribute to the expression of a phenotype in a additive manner, they are called additive alleles. This means that each gene adds a certain amount to the expression of the phenotype, and the total effect is the sum of each gene's contribution.