Question

what is a top - down cascade? a) an effect on primary producers caused by a change in apex predators b) an effect on apex predators caused by a change in primary producers c) an effect on apex predators caused by a change in abiotic resources d) an effect on primary producers caused by a change in abiotic resources

Explanation:

A top - down cascade refers to a trophic cascade that starts from the top of the food chain. A change in apex predators (top - level consumers) has a cascading effect down the food chain, ultimately impacting primary producers. For example, if apex predators decline, the population of their prey (herbivores) may increase, which can then over - graze primary producers.

Answer:

A. An effect on primary producers caused by a change in apex predators