Question

n humans, red blood cells have a number of proteins embedded in the cell membrane. One type of protein, the Rhfactor, is controlled by a single gene and is either present or missing from the red blood cells. If present, the individual has the Rh+phenotype. If missing, the individual has the Rh-phenotype. Rh+is the dominant to Rh-. Suppose that, in the Welsh population, the frequency of the Rh-phenotype is 0.04. Using the Hardy-Weinberg equations, calculate the frequency of the Rh+allele.

Answer 1

The frequency of the genotype dd (q²) is .04

From this, we can estimate q as: q = = = 0.2

The allele frequency of D is: p = 1 - q = 1 - 0.2 = 0.8

Assuming HWE, genotype frequencies are as follows:

DD = p² = 0.64, Dd = 2pq = 2 x 0.2 x 0.8 = 0.32, dd = q² = 0.04

So, the frequency of the Rh+ allele (p) = 0.8