22. Which of the following best describes the impact of a trophic cascade on an ecosystem? A) It only affects the population of the top predator B) It can lead to significant changes in the structure and function of the ecosystem C) It has no long-term effects on the ecosystem D) It only affects the primary producers

The answer is **B) It can lead to significant changes in the structure and function of the ecosystem.**<br /><br />Here's why:<br /><br />A trophic cascade describes the indirect effects of a top predator on lower trophic levels. Changes in the top predator population can ripple down through the food web, impacting not just their prey, but also the prey's prey, and so on. These impacts can alter the abundance and behavior of species at multiple trophic levels, leading to changes in things like plant community structure, nutrient cycling, and overall ecosystem productivity.<br /><br />Let's look at why the other options are incorrect:<br /><br />* **A) It only affects the population of the top predator:** This is incorrect because the cascade effect impacts multiple trophic levels *below* the top predator.<br />* **C) It has no long-term effects on the ecosystem:** Trophic cascades can have profound and lasting impacts on ecosystem structure and function.<br />* **D) It only affects the primary producers:** While primary producers are often affected, the impact extends to other trophic levels as well, including herbivores and intermediate predators.<br />