Organisms and Populations Question 9
9. What is a keystone species?
[2004]
(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 organization and survival
(b) A common species that has plenty of biomass, yet has a fairly low impact on the community’s organization
(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.
Show Answer
Answer : a
Hints & Solutions
(a) A keystone species is the one 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. Some examples of keystone species are as follows:
- Shark is an avid predator that feeds on fishes of all kinds making it the keystone species in deep waters.
- Sea otter a mammal in the North Pacific Ocean, which feeds on sea urchins thus maintaining the coastal marine ecosystem.
- Snowshoe haresare prey for a lot of predators in the Canadian Boreal forests
- The African elephant is the biggest mammal on land is also a keystone species. It is found in Africa. Its role is in its destructive force on trees and consumption of young saplings of the savannah grasslands.
