OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

In what way do tigers influence their ecosystem?

1. By competing with herbivores for food

2. By controlling populations of prey species

3. By promoting the growth of grasses

4. By forming groups to hunt more effectively

The correct answer is: By controlling populations of prey species

Tigers play a crucial role in their ecosystem primarily through their role as apex predators. By controlling populations of prey species, they help maintain a balance within the ecosystem. When tiger populations are healthy, they regulate the number of herbivores, such as deer and wild boar. This prevents overgrazing, allowing vegetation to thrive and supporting the overall health of the ecosystem. The presence of tigers contributes to what is known as a trophic cascade, where changes at the top of the food chain can impact multiple levels of the ecosystem below them. If tiger numbers decline, prey populations can increase unchecked, leading to significant overconsumption of plant life, which in turn can alter habitats and affect many other species that rely on those plants. This demonstrates the integral part tigers play in maintaining ecological balance and biodiversity.