Question

African elephants push over or remove small acacia trees that sprout among the grasses in grasslands where they roam. The elephants’ action prevents the trees from getting too large and shading out the important grasses they consume. Because the roots of the grasses run deep into the ground, they are able to continue to grow even when the shoots above the ground are eaten. This best describes the role of Africa elephant as
A. A keystone species
B. A producer
C. A decomposer
D. A scavenger
E. A secondary consumer

Answer 1

Hint: An ecosystem can be described as the interaction of living organisms of a community with one another and also with their abiotic environment. In an ecosystem, all the organisms have specific functional roles which are important for the proper functioning of the ecosystem.

Complete answer:
-A keystone species is the one that plays an important role in the functioning of an ecosystem. The absence of these species affects the normal functioning of the ecosystem.
-Producers or autotrophs are the organisms that inorganic compounds like carbon dioxide and water into organic compounds like carbohydrates in the presence of radiant energy of the sun, carbon dioxide and water by the process of photosynthesis.
-Decomposers are the organisms that break down the organic compounds of animal’s wastes and dead bodies of producers and macroconsumers. This helps in releasing inorganic compounds back into the environment by the process of decomposition and mineralization which helps in mineral cycling.
-Consumers are those heterotrophic animals that consume the producers directly or indirectly. So these include herbivores and carnivores also. Carnivores can be described as secondary consumers as they consume primary consumers i.e. herbivores.
-Scavengers are the organisms that feed on dead organisms.
So, the correct answer is “Option A”.

Note: According to David Tilman, a community with more species is more stable than those containing less number of species. A stable community is one that does not show much variation and is resistant to seasonal disturbance and alien species.