Which trait is an example of incomplete dominance in humans?

• A. Blue eyes
• B. Freckles
• C. AB blood type
• D. Wavy hair

Answer: (D)

Verified step by step guidance

1. Understand the concept of incomplete dominance: Incomplete dominance occurs when the phenotype of the heterozygote is intermediate between the phenotypes of the homozygotes. This means that neither allele is completely dominant over the other, resulting in a blend of traits.
2. Identify examples of incomplete dominance in humans: Incomplete dominance can be observed in traits where the heterozygous genotype results in a phenotype that is a mix of the two homozygous phenotypes.
3. Consider the trait of wavy hair: Wavy hair is an example of incomplete dominance because it is a blend between curly hair and straight hair. Individuals with one allele for curly hair and one allele for straight hair often have wavy hair.
4. Compare wavy hair to other traits: Blue eyes, freckles, and AB blood type do not exhibit incomplete dominance. Blue eyes and freckles are typically examples of simple dominance, while AB blood type is an example of codominance, where both alleles are expressed equally.
5. Conclude that wavy hair is the correct example of incomplete dominance: Based on the understanding of incomplete dominance, wavy hair fits the criteria as it results from the blending of two different hair textures.