Question

Following a flood, migration from neighboring populations alters genotypic frequencies of a population of river-bottom midges. Assuming that the conditions for Hardy–Weinberg subsequently are met, how many generations of random mating are required to restore the genotypic frequencies to Hardy–Weinberg equilibrium?(A) Between 3 and 10(B) Between 11 and 20(C) 2(D) 1(E) More than 20

Answer 1

Answer: D

Explanation: Hardy-Weinberg (H-W) principle assumes the following;

1. Random mating

2. No migration

3. No selection

4. No mutation

5. Large population

When genotype frequencies in a population deviate from H-W principle, it takes only one (1) generation of random mating to H-W equilibrium if the above assumptions hold, that the frequencies in males and females are equal and that the locus is autosomal.

In the case of different allele frequencies between the sexes, it will take two (2) generations of random mating to H-W equilibrium.

Also, it will take multiple generations to attain equilibrium for sex-linked loci because one sex has two copies of the gene and the other sex has only one.