Question

In fruit flies, straight wing shape is dominant to curly wing shape. A particular population of fruit flies is in Hardy-Weinberg equilibrium with respect to the alleles for wing shape. The Hardy-Weinberg equation, given below, is useful in understanding population genetics: P2 + 2pq + q2 = 1
a. Explain what the terms (p2, 2pq, and q2) represent in the population of fruit flies?
b. Describe one condition that is necessary for the population to be in equilibrium?

Answer 1

Answer:

a) p² = homozygous dominant genotype frequency

   2pq = heterozygous genotype frequency

   q² = homozygous recessive genotype frequency

b) the population must be randomly mating.

Explanation:

(a) The formula for genotype frequency of a population with p and q alleles is as under:

        p² + 2pq + q²  = 1

where p allele is dominant over q allele.

Phenotypically p² + 2pq will produce same appearance i.e. dominant phenotype while q² will produce recessive phenotype. So it means that if 80% population is represented by p² + 2pq then 20% will be represented by q².

(b) One of the conditions for a population to be in Hardy-Weinberg equilibrium is that the population must be randomly mating.