Question

Which of the following statements describes a population at genetic equilibrium?

• A. A population in which there are equal numbers of dominant and recessive alleles
• B. A population in which allele frequencies remain constant from generation to generation
• C. A population in which mutations occur causing allele frequencies to remain constant over generations
• D. A population in which immigration and emigration cause allele frequencies to remain constant from generation to generation
• E. A population in which there is sexual selection

Answer 1

The correct option is B A population in which allele frequencies remain constant from generation to generation

The Hardy-Weinberg law or Hardy-Weinberg theorem or Hardy-Weinberg equilibrium is the fundamental law of population genetics which provides the basis for studying the Mendelian populations. This law was independently developed by GH Hardy, an English mathematician and G Weinberg, a German physician in 1908. This law states that genes and genotypic frequencies in a mendelian population remain constant generation after generation, if there is no selection, mutation, migration or random drift.

Thus the original proportions of the genotype in a population will remain constant from generation to generation, as long as the following assumptions are met:

1. The population size is very large.

2. No genes are input from other sources i.e. no gene flow takes place.

3. No mutation takes place.

4. No natural selection occurs.

5. Random mating is occurring.

Hence a population is at genetic equilibrium when allele frequencies remain constant from generation to generation.

So, the correct answer is 'A population in which allele frequencies remain constant from generation to generation'.