Red-green colour blindness in human is caused by an X-linked recessive allele if the trait occur in 4 of the males in a population at Hardy-Weinberg equilibriumthen the frequency of this allele is?

Answer 1

If 4% of males in a population have red-green color blindness, then the allelic frequency is 4% in males and in females. If mating is random, then in females, 92.16% do not carry the allele on either X chromosome, 7.68% carry the allele on one X chromosome, and 0.16% carry the allele on both X chromosomes. We have the dominant allele with frequency p and the recessive allele with frequency q, so 0.9216 + 0.0768 + 0.0016 = p^2 + 2pq + q^2 = (p + q)^2 = (0.96 + 0.04)^2

Answer 2

Since red-green color blindness is X-linked recessive, the trait affects males more frequently than females. If 4 out of 100 males are affected, then the frequency of the recessive allele can be calculated using the Hardy-Weinberg equation: q^2 = 0.04 (since males are hemizygous for X-linked traits). Taking the square root of 0.04 gives q = 0.2, which is the frequency of the recessive allele.