Question

You have read about food chains in this chapter. Each living thing is a part of multiple food chains – for example, grass is a part of the food chain: grass → grasshopper → frog → snake → eagle, and also of the food chain: grass → deer → tiger.
All of the interconnected and overlapping food chains in a habitat make up a food web.



See the given food web and answer these questions.
1. From the food web, construct two different food chains, each with four links.
2. If all the eagles were killed, what would happen to the number of

a. squirrels?
b. earthworms?

Answer 1

1. Food chain I -

Roots →Earthworms→Sparrows →Eagles

Food chain II -

Berries →Flies →Frog →Eagles

2. Eagles keep a check on the population of squirrels. If all the eagles are killed, the population of squirrels would increase tremendously. An increase in the population of squirrels mean large scale destruction of nuts, the products on which they primarily feed on.

Eagles also feed on sparrows and keep a check on their population as well. Killing of eagles means, increased population of sparrows. As, the population of sparrows would increase, so will their demand for food. They feed on earthworms and large scale consumption of these may result in the extinction of earthworms. Also, earthworms are called a farmer's friend. In their absence, the agriculture would also be affected.