In incomplete dominance, a cross between red-flowered and white-flowered plants yields which color in the offspring?

• A. White
• B. Red
• C. Lilac
• D. Pink

Answer: (D)

In incomplete dominance, the heterozygous genotype shows a phenotype that is intermediate between the two homozygous phenotypes. Red-flowered plants are typically homozygous for the red allele, and white-flowered plants are homozygous for the white allele. When they cross, the offspring are heterozygous, carrying one red allele and one white allele. Because neither allele fully dominates, the pigment blend produces pink instead of red or white. So the offspring appear pink. If one allele were completely dominant, you’d see red or white; if both colors were expressed separately (codominance), you’d see a different pattern, not the smooth pink blend seen here.