Question

decline of a keystone species can disrupt the delicate balance of the food web, and even lead to ecosystem - wide collapse. examples of keystone species include sea otters and alligators. alligators are considered a keystone species in specific parts of florida. what does this mean? it disproportionately degrades the structure and functioning of its local florida ecosystem. it means the alligators are totally normal, niche filling species, in florida. it disproportionately influences the structure and functioning of its local florida ecosystem.

Explanation:

A keystone species has a large impact on its ecosystem relative to its abundance. As stated in the text, a decline in a keystone species can disrupt the food web and even lead to ecosystem - wide collapse. This implies that the species has a significant (disproportionate) influence on the ecosystem's structure and functioning. The first option is incorrect as it mentions "degrades" which is the opposite of the positive (or at least important) role of a keystone species. The second option is wrong because it says the species is "totally normal, niche - filling" which does not align with the definition of a keystone species having a more crucial role.

Answer:

It disproportionately influences the structure and functioning of its local Florida ecosystem.