Question 11
When the wolves were eliminated from the Yellowstone ecosystem, how was the population of plants indirectly affected?
Correct Response: The elk, which were prey for the wolves, did not have a predator maintaining their population size, so overgrazing of plants occurred.
Question 12
Drag each answer choice to the blank that completes the paragraph correctly.
Wolves are considered keystone species because they are a species that other plants and animals within an ecosystem largely depend on. They are also top-level predators (predators at the top of the food chain) and greatly influence their environment. The removal of wolves from the ecosystem would drastically change and possibly collapse the ecosystem because no other species is able to fill the wolves' ecological niche.
When the last remaining wolf pups in Yellowstone were killed in 1924, it started a top-down process called a trophic cascade, which is an ecological process that starts at the top of the food chain and affects other organisms all the way down the food chain. This is a change that results from the removal of an ecosystem's top-level predators or keystone species.
Question 13
Taking what you learned about the wolves in Yellowstone, if all wolves were suddenly removed from the imaginary island mentioned in #2-#10, what would happen to the deer population?
Correct Response: The deer population would probably grow like it did prior to 2010 until starvation and disease began to limit the population similar to how the deer affected Yellowstone before the wolves were reintroduced.