Several alleles at several different loci all contribute additively to the same trait.Therefore,for this trait:
A) homozygotes cannot exist
B) heterozygotes cannot exist
C) only one phenotypic class is possible
D) only two phenotypic classes are possible
E) continuous variation may be observed

Question

Quizplus · Accepted Answer

If several alleles at several different loci all contribute additively to the same trait, then continuous variation may be observed. This means that there can be a wide range of phenotypic classes, rather than just one or two distinct classes. Homozygotes and heterozygotes can still exist, but the presence of multiple loci and alleles means that there will be more complexity in the expression of the trait.

Several Alleles at Several Different Loci All Contribute Additively to the Same