When neither allele masks the expression of the other

• A. Complete dominance
• B. Incomplete dominance
• C. Codominance
• D. Polygenic inheritance

Answer: (B)

In this idea, neither allele is fully dominant over the other. The heterozygous genotype produces a phenotype that is intermediate between the two homozygous phenotypes because both alleles contribute to the trait. A classic example is a flower color cross where red and white alleles blend to pink in the offspring: red homozygotes are red, white homozygotes are white, and heterozygotes are pink. This differs from complete dominance, where one allele fully masks the other, and from codominance, where both alleles are expressed distinctly rather than blending. Polygenic inheritance involves many genes influencing a trait, not just a single pair of alleles.