Question

Select the correct statement:

• A. Hardy-Weinberg law is applicable to small populations
• B. Sewall Wright effect is applicable to large populations
• C. Development of resistance to DDT by mosquitoes is an example for directional selection
• D. If one species diverges to become two or more species, it is called anagenesis

Hint:

Directional selection can lead to significant changes in population characteristics over time, especially under strong selective pressures.

Answer 1

The Correct Option is C

Option (1): The Hardy-Weinberg law applies to large populations, not small populations. It assumes that allele frequencies in a population remain constant over generations in the absence of evolutionary influences.
Option (2): The Sewall Wright effect (also known as genetic drift) is more significant in small populations, not large ones.
Option (3): The development of resistance to DDT by mosquitoes is an example of directional selection. Over time, mosquitoes with resistance to DDT survive and reproduce, increasing the frequency of resistant alleles in the population.
Option (4): The process of one species diverging into two or more species is known as cladogenesis, not anagenesis. Anagenesis refers to the evolution of a single species over time without branching.
Thus, option (3) is the correct answer, as the resistance to DDT in mosquitoes is a clear example of directional selection.