Ontario Grade 9 Science Class Practice Exam

What is a limiting factor in an ecosystem?

1. A nutrient that is overly abundant in an ecosystem.

2. A type of animal that dominates an ecosystem.

3. An environmental factor that prevents a population from increasing.

4. A factor that increases biodiversity.

The correct answer is: An environmental factor that prevents a population from increasing.

A limiting factor in an ecosystem refers to an environmental factor that restricts the growth or distribution of a population within that ecosystem. This can include factors such as food, water, shelter, and space. Options A, B, and D are incorrect because they do not accurately define a limiting factor. Option A talks about an abundant nutrient, but this does not necessarily restrict the growth of a population. Option B mentions a dominant animal, which also does not necessarily limit the growth of other populations. Option D refers to a factor that increases biodiversity, but this does not necessarily limit the growth of a specific population. Therefore, the correct answer is option C, as it accurately describes the definition of a limiting factor.