In incomplete dominance, which statement is true?

In incomplete dominance, which statement is true?

• A. Neither allele is dominant
• B. One allele is dominant over the other
• C. The heterozygote expresses neither phenotype
• D. The trait is influenced only by environmental factors

Answer: (A)

In incomplete dominance, neither allele is completely dominant over the other. The heterozygote displays an intermediate phenotype between the two homozygous forms. For example, crossing red-flowered and white-flowered snapdragons gives pink offspring, showing a blend rather than red or white being fully expressed. This differs from a situation where one allele is dominant, which would make the heterozygote look like one of the homozygotes. It also isn’t that the heterozygote shows no phenotype at all—the trait is expressed, just as an intermediate form. Environmental factors alone don’t explain this genetic pattern.

In incomplete dominance, neither allele is completely dominant over the other. The heterozygote displays an intermediate phenotype between the two homozygous forms. For example, crossing red-flowered and white-flowered snapdragons gives pink offspring, showing a blend rather than red or white being fully expressed. This differs from a situation where one allele is dominant, which would make the heterozygote look like one of the homozygotes. It also isn’t that the heterozygote shows no phenotype at all—the trait is expressed, just as an intermediate form. Environmental factors alone don’t explain this genetic pattern.