A Level Biology Practice Exam

What does 'variation' mean in a biological context?

1. Changes in the genetic material of an organism

2. The presence of variety among organisms or traits

3. The process of natural selection acting on a population

4. The difference in the environment affecting species

The correct answer is: The presence of variety among organisms or traits

In a biological context, 'variation' specifically refers to the differences that exist among individuals within a population or species. This variation can be in terms of physical characteristics, behaviors, biochemical processes, or genetic sequences. The presence of variety, which encompasses these differences, is crucial for evolution and survival, as it provides a pool of traits that can be acted upon by natural selection. While changes in genetic material (as seen in mutations) can lead to variation, the term 'variation' itself encompasses a broader scope that includes any type of differences, whether they are genetic, morphological, or functional. Natural selection, while a vital process influencing variation, is not itself a definition of variation but rather a mechanism that acts on the existing variations. Similarly, environmental differences can cause variations in traits, but the core definition of variation focuses primarily on the differences between organisms or traits rather than external influences. Thus, option B accurately captures the essence of what variation means in biology.