Biology Regents Practice Exam

What is an example of a biotic factor in an ecosystem?

1. Soil composition

2. Temperature fluctuations

3. Supply of water

4. Species interactions

The correct answer is: Species interactions

A biotic factor in an ecosystem refers to any living component that affects other organisms or the environment itself. Species interactions are a prime example of biotic factors because they include relationships such as predation, competition, symbiosis, and mutualism among organisms. These interactions are crucial for understanding how populations influence one another and how energy and nutrients flow through an ecosystem. In contrast, soil composition, temperature fluctuations, and supply of water are classified as abiotic factors because they pertain to non-living elements of the environment. These abiotic factors can influence living organisms, but they do not involve interactions between living organisms themselves, which is why they are not considered biotic. The relationship within ecosystems is complex, with biotic factors interacting with both abiotic factors, playing a significant role in shaping the structure and function of ecological communities.