Which inheritance pattern explains a cross yielding red, white, and pink offspring in the F2 generation?

Which inheritance pattern explains a cross yielding red, white, and pink offspring in the F2 generation?

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

Answer: (C)

Incomplete dominance is shown when the heterozygote displays a phenotype that is intermediate between the two homozygotes. If red and white alleles follow this pattern, crossing red with white gives pink offspring in the first generation. When pink individuals are crossed among themselves, the offspring in the second generation appear red, pink, and white in a 1:2:1 ratio. This distinct 1:2:1 phenotypic pattern in the F2 is a hallmark of incomplete dominance. In contrast, complete dominance would produce offspring that look like one parent plus a 3:1 ratio in the F2, codominance would show both parental phenotypes simultaneously in the heterozygote (not a blended pink), and polygenic inheritance would typically yield a continuous range of phenotypes rather than distinct colors.

Incomplete dominance is shown when the heterozygote displays a phenotype that is intermediate between the two homozygotes. If red and white alleles follow this pattern, crossing red with white gives pink offspring in the first generation. When pink individuals are crossed among themselves, the offspring in the second generation appear red, pink, and white in a 1:2:1 ratio. This distinct 1:2:1 phenotypic pattern in the F2 is a hallmark of incomplete dominance. In contrast, complete dominance would produce offspring that look like one parent plus a 3:1 ratio in the F2, codominance would show both parental phenotypes simultaneously in the heterozygote (not a blended pink), and polygenic inheritance would typically yield a continuous range of phenotypes rather than distinct colors.