What is keystone species ?

Options

A. A common species that has plenty of biomass, yet has a fairly low impact on the community's organisation.
B. A rare species that has minimal impact on the biomass and no other species in the community.
C. A dominant species that constitutes a large proportion of the biomass and which effects many other species
D. A species which makes only a small proportion of the total biomass of a community, yet has a huge impact on community's organisation and survival

Answer

D