What is a keystone species?

Options

A. 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 organisation and survival
B. A common species that has plenty of biomass, yet has a fairly low impact on the community's organisation
C. A rare species that has minimal impact on the biomass and on other species in the community
D. A dominant species that constitutes a large proportion of the biomass and which affects many other species

Answer

A

Explanation

Species having much greater influence on community characteristics, relative to their low abundance or biomass are keystone species, removal of these cause serious disruption in functioning of community, e.g. in tropical forests, figs are keystone species.