Can you help me ? Colorblindness is a recessive sex-linked trait. Assumethat there is no selection for or against colorblindness. Thefrequency of the colorblind allelle "c" in US populations is0.028. What is the proportion of men who arecolorblind? Of Women? Show your work. Assume HWequilibrium. Can you help me ? Colorblindness is a recessive sex-linked trait. Assumethat there is no selection for or against colorblindness. Thefrequency of the colorblind allelle "c" in US populations is0.028. What is the proportion of men who arecolorblind? Of Women? Show your work. Assume HWequilibrium.
Explanation / Answer
1. Let us consider C gene for normalvision. 2. Thus C or c have equal probability (1/2)as nogene is preferred over the other. 3. A female will be colourblind only if shehas cc genes on bothethe X chromosomes. (heterozygous females i.e. Cc have normalvision) 4. Thus the probability becomes 1/2 X 1/2 =1/4. 5. A male has only one X chromosome, so ifhe has one c gene then he becomes coloublind, i.e. 1/2probability. 6. Thus ccording to HW peinciple frequencyof c is 0.028 i.e. 2.8% people carry c gene. 7. Out of these 1.4% will be men and will becolorblind. 8. Whereas out of 1.4% women carryingthe allele only .7% will be homozygous andthus colourblind.