A Level Biology Practice Exam

Which process describes how organisms better suited to their environment reproduce successfully?

1. Genetic drift

2. Natural selection

3. Adaptive radiation

4. Species extinction

The correct answer is: Natural selection

The concept of natural selection describes the process whereby organisms that are better adapted to their environment have a higher likelihood of surviving and reproducing. This mechanism was famously formulated by Charles Darwin and is fundamental to the theory of evolution. In natural selection, individuals with traits that confer advantages in a specific environment tend to produce more offspring than those without such traits. Over time, these advantageous traits become more common within the population, leading to evolutionary changes. This process is a critical driver of the diversity of life and the adaptation of species to their ecological niches. Other processes such as genetic drift, adaptive radiation, and species extinction do not specifically describe the mechanism by which adaptation leads to successful reproduction. Genetic drift focuses on random changes in allele frequencies, adaptive radiation refers to the diversification of a species into various forms adapted to different environments, and species extinction pertains to the disappearance of species rather than their successful reproduction. Thus, natural selection is the most accurate description of how organisms that are well-suited to their environments can increase their reproductive success.