Ontario Grade 9 Science Class Practice Exam

What impact do invasive species have on ecosystems?

1. They improve biodiversity

2. They have no impact

3. They harm native species and habitats

4. They enhance soil fertility

The correct answer is: They harm native species and habitats

Invasive species can cause harm to native species and their habitats by outcompeting them for resources, introducing new diseases, and altering the natural balance of the ecosystem. This can lead to negative cascading effects on other organisms and disrupt the overall functioning of the ecosystem. Options A and D are incorrect because invasive species do not improve biodiversity or enhance soil fertility, as they often dominate and push out other native species. Option B is incorrect because, as mentioned, invasive species can have significant and damaging impacts on ecosystems.