Question

Which of the following is a bottom-up factor that could impact the population sizes of these herbivores?

a. predators, such as lions b. parasites c. rainfall OR d. earthquakes

Answer 1

The answer is C) rainfall. Rainfall impacts plants, which these animals depend on for food, and is thus a bottom- up factor. The number of lions or parasites may also affect a population's size, but they are top-down factors instead.