If an allele has the same phenotypic effect in heterozygotes as in homozygotes-that is,the genotypes Aa and AA are phenotypically indistinguishable then the allele is:
A) Recessive
B) Dominant
C) Incompletely dominant
D) Codominant
E) Partially dominant

Question

Quizplus · Accepted Answer

If the heterozygote (Aa) has the same phenotype as the homozygote (AA), then the dominant allele (A) is expressed regardless of the presence of the recessive allele (a). This confirms that the dominant allele masks the expression of the recessive allele.

If an Allele Has the Same Phenotypic Effect in Heterozygotes