He expression of both alleles for a trait in a heterozygous individual illustrates what?

Question

He expression of both alleles for a trait in a heterozygous individual illustrates what?

Answer 1

If the phenotype (visible trait) shows both alleles, if they are different genotypes.  An example of this would be blood type.  More easily visible is hair color with brown and blonde being codominant which may  produce either brown, blonde or red hair.

Answer 2

condominance.. i guess this question has been answered already by the person above me..

Answer 3

that there are both dominate and recessive alleles

Answer 4

codominance