Question

Q. The frequency of a recessive allele in a large randomly mating population is 0.2. What is the frequency of: (a) The dominant allele? (b) The heterozygote?

Answer 1

According to the given details in the question, the frequency of the recessive allele in a random mating population = 0.2.

(a) Since the whole population is considered = 1, the dominant allele should be present in the population in a number that leaves the recessive allele out.

So, dominant alleles + recessive alleles = 1

Dominant alleles + 0.2 = 1

Dominant alleles = 1 - 0.2 = 0.8

Thus, Dominant alleles = 0.8.

(b). The frequency of heterozygosity - There is a minimum of 2 heterozygous alleles in a mating population.

So, Heterozygosity = 2 x 0.8 x 0.2 = 0.32.

Thus, the frequency of the heterozygous carriers will be = 0.32.