In: Biology
7. The phenotypic frequency of colorblind males in the Caucasian population is 0.08. If the population is in equilibrium, what percentage of women would we expect to be color blind in this population? (give only number with % sign, do not write a sentence).
Percentage of women expected to be colorblind (homozygous for mutant X-allele) = 0.6%
Explanation:
Colorblindness is inherited in an X-linked recessive pattern.
The frequency of colorblind males in the Caucasian population is 0.08, so the percentage of colorblind hemizygous males in the population is 8% (q=0.08).
Since the population is in equilibrium, the proportion of male and females are equal, so the frequency of heterozygous carrier females will be 0.08.
Applying the Hardy-Weinberg equation,
p2+2pq+q2
q2 will be (0.08)2 = 0.0064
= 0.6%
The proportion of homozygous recessive mutant alleles would be 0.6% of the population and since it is X-linked, they would all be females with colorblindness.
Expansion the equation to the entire population:
p + q = 1
p = 1 - 0.08
p = 0.92
p2+2pq+q2
(0.92)2 + 2 (0.92) (0.08) + (0.08)2
0.8464 + 0.1472 + 0.0064