Answer:
The frequency of undimpled tasters is 0.136.
Explanation:
The Hardy-Weinberg law illustrated all the probable genotypes for a gene with two alleles. The binomial expansion signifying this is, p2+2pq+q2 = 1.0
Here, p2 is the proportion of homozygous dominant individuals, q2 refers to the proportion of homozygous recessive individuals, and 2pq is the proportion of heterozygotes.
Thus, on the basis of the given data, the frequencies for dimples phenotypes are:
The frequency of homozygous dominant allele carrying individuals (DD) = 0.62 * 0.62 = 0.3844
The frequency of heterozygous allele carrying individuals (Dd) = 2 * 0.62 * 0.38 = 0.4712
The frequency of homozygous recessive allele carrying individuals (dd) = 0.38 * 0.38 = 0.1444
Thus, from the above frequencies, the frequency of individuals with dimples (DD and Dd) = 0.3844 + 0.4712 = 0.8556
The frequency of individuals without dimples (dd) = 0.1444.
The frequencies for tasting phenotypes:
The frequency of homozygous dominant allele carrying individuals (TT) = 0.76 * 0.76 = 0.5776
The frequency of heterozygous allele carrying individuals (Tt) = 2 * 0.76 * 0.24 = 0.3648
The frequency of homozygous recessive allele carrying individuals (tt) = 0.24 * 0.24 = 0.0576
Thus, from the above frequencies:
The frequency of individuals with taste for PTC (TT and Tt) = 0.5776 + 0.1824 = 0.944
The frequency of individual without taste for PTC (tt) = 0.0576
As it is a dominant mode of inheritance the genotype of undimpled tasters is either ddTt or ddTT.
The frequency of taster individuals will be TT + Tt = 0.5776 + 0.3648 = 0.9424
Now, the expected frequency of undimpled tasters will be the product of frequency of dimpled and frequency of tasters = 0.144 * 0.9424 = 0.1357.
Therefore, the frequency of the undimpled tasters is 0.136.