As a geneticist with a focus on human genetics, I can tell you that red hair is indeed associated with a recessive gene. The gene in question is the MC1R gene, which is responsible for producing a protein that influences hair color. When a person inherits two recessive alleles of the MC1R gene—one from each parent—they are likely to have red hair. However, the expression of red hair can be influenced by other genes and environmental factors as well.

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In genetics speak, we'd say that some alleles are recessive and some are dominant. The red hair versions of the MC1R gene are recessive to the other MC1R versions. So if you have a red and a non-red version of the MC1R gene, then you won't have red hair.read more >>