Keystone species deserve protection because these

(1)  are capable of surviving in harsh envinmental conditions

(2)  indicate presence of certain mineral in the soil

(3)  have become rare due to over exploitation

(4)  play an important role in supporting other species.

What is a keystone species?

(1) A species which makes up only a small proportion of the total biomass of a community, yet has a huge impact on the community's organization and survival,

(2) A common species that has plenty of biomass, yet has a fairly low impact on the community's organization

(3) A rare species that has minimal impact on the biomass and on other species in the community.

(4) A dominant a large proportion of the biomass and which affects many other species.

A keystone species is one that:

(1) Has a higher likelihood of extinction than a non keystone species

(2) Exerts a strong influence on an ecosystem

(3) Causes other species to become extinct

(4) Has a weak influence on an ecosystem

Who among the following gave tentative answers to the question that how do the attributes of a stable community are linked to species richness in a community?

Rich biodiversity is not important for