Question

Which of the following statements are correct with respect to food chains in an ecosystem?
I) Removal of 80% of tigers from an area will result in an increased growth of vegetation.
II) Removal of most of the carnivores will result in an increased population of deers.
III) The length of food chain is generally limited to 3 - 4 trophic levels in an ecosystem.
IV) Topmost trophic level possess the maximum energy.

• A. II and III
• B. III and 1V
• C. I and IV
• D. I and II

Answer 1

The correct option is A II and III

$\bullet$ In a grazing food chain, the producers are eaten by herbivores and the herbivores are eaten by carnivores. Therefore, the removal of most of the carnivores will result in an increased population of deer which in turn will affect the vegetation in that area.
$\bullet$ According to the 10% law, only 10% energy from the organic matter is transferred from one trophic level to next trophic level. As a result of this, energy available at the third of fourth trophic level becomes very less to support any further trophic level. Thus, number of trophic level in a food chain is limited to 3 or 4.