When Two Alleles for the Same Trait are Both Expressed

Question

When two alleles for the same trait are both expressed, you know that
A) both alleles are recessive.
B) one allele is dominant.
C) the alleles are codominant.
D) the alleles are heterozygous.

Accepted Answer

When two alleles for the same trait are both expressed, it indicates that the alleles are codominant, meaning that both traits are simultaneously expressed. This is in contrast to incomplete dominance, where a blending of traits occurs, or complete dominance, where one trait is dominant and the other is recessive.