Question

Which of the following best describes a keystone species?

Can indirectly protect several other species in the same habitat

An organism, who if removed, the entire ecosystem changes

Can signal a change in the biological condition of a particular ecosystem and diagnose the health of that ecosystem

An organism, whose introduction causes or is likely to cause environmental harm

Answer 1

An organism, who if removed, the entire ecosystem changes

Step-by-step explanation:

A keystone species is a species which has a disproportionately large effect on its natural environment relative to its abundance, a concept introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf, are also apex predators.