Question

A polygenic trait is:

• A. Blood group in humans
• B. Hair color in humans
• C. Skin color in humans
• D. Coat color of cats

Answer 1

Answer:

C. Skin color in humans

A polygenic trait is a characteristic that is influenced by two or more genes. Unlike a trait controlled by a single gene, polygenic traits often show a wide range of variation and are expressed as a continuous distribution of phenotypes (e.g., a bell-shaped curve).

• Skin color is determined by at least three different gene pairs, which contribute to the amount of melanin produced. The more dominant alleles an individual has, the darker their skin tone.

• Blood group in humans is an example of multiple alleles and codominance, not polygenic inheritance.

• Hair color in humans is more complex but is also influenced by multiple genes.

• Coat color of cats is often an example of traits controlled by one or two genes, with some exceptions.