Question

keystone species
predation can have far - reaching effects on biological communities. a starfish is the top predator in tidepool communities in the pacific northwest. the community also includes mollusks, barnacles and other invertebrates. in a classical experiment involving starfish, an investigator removed the starfish from a tide pool. soon, barnacles and mussels began to occupy all available space in the tidepool, out - competing other species. species diversity (number of different species) in the tidepool dropped by over 50%. the starfish was a keystone predator, keeping the strongest predators in check. although it was a predator, it helped to maintain a greater number of species in the community. its beneficial impact on species that were weak competitors is an example of an indirect effect. (umich)

1. a keystone predator is one that

highlight the correct answer in yellow
a. keep other predators in check\tc. hunts all the prey
b. opens the locks in the ocean\td. gets old and dies the slowest

Explanation:

The text says a keystone predator (starfish) keeps the strongest predators in check. Option A matches this. B is irrelevant, C is incorrect (it maintains diversity, not hunt all prey), D is unrelated.

Answer:

A. Keep other predators in check