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

Migration after a flood can disrupt the genotypic frequencies of a population. In order to restore the genotypic frequencies to Hardy-Weinberg equilibrium, multiple generations of random mating will be needed. The exact number of generations required will depend on the extent of the frequency changes.

Step-by-step explanation:

In this scenario, migration from neighboring populations alters the genotypic frequencies of a population of river-bottom midges after a flood. To restore the genotypic frequencies to Hardy-Weinberg equilibrium, random mating is required.

The Hardy-Weinberg equilibrium principle states that, under certain conditions, the allele and genotype frequencies in a population remain constant from generation to generation in the absence of evolutionary forces. These conditions include no mutation, no migration, a large population size, random mating, and no natural selection.

In this case, since migration has disrupted the genotypic frequencies, random mating over multiple generations will be needed to restore the frequencies to Hardy-Weinberg equilibrium. The number of generations required depends on the extent of the genotypic frequency changes and can vary. However, it is likely to take more than 20 generations of random mating to restore the genotypic frequencies to equilibrium.

Answer 2

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.