One day, Ganesh asked his father why is government so much worried about decreasing population of tigers ? His father replied that it is important to save the tiger as they are at the end of food chains in forest ecosystem and play a role to keep the biotic components in ecosystem in balance.
Read the above passage and answer the following questions:
(i) What is a food chain ?
(ii) What is an ecosystem ?
(iii) What value is displayed by Ganesh's father?

Avinash went to his village during his summer vacations. One day, he decided to visit the nearby forest and asked his grandfather to accompany him. His grandfather told him about the recent cutting of forest and the new factory which had been established. Hearing this Avinash became curious and explained his grandfather about the ecosystem services.
(i) What are the benefits of healthy forest ecosystem?
(ii) Explain the contribution of Robert Constanza in ecosystem services.
(iii) What factors account for cost of various ecosystem services?
(iv) What values are shown by Avinash?

Arun visited his grandfather's farm and noticed that one of the workers was introducing earthworms in the soil. He quickly rushed to his grandfather and asked him the reason. His grandfather explained him the advantages of earthworm in soil improvement.
(i) Why are earthworms also known as detritivores?
(ii) Explain fragmentation.
(iii) Name the steps in the process ofdecomposition.
(iv) What values are shown by Arun?

Jeremy went to a butcher's shop with his father and saw that the goats before slaughter were fed on grasses and was fascinated to see the sequence of organism through which the food passes. On seeing his fascination his father asked him the reason and he quickly explained him the concept of food chain.
(i) Describe food chain.
(ii) Grass was eaten by goat which in turn is consumed by humans. Explain their relation.
(iii) Name different types of food chains.
(iv) What values are shown by Jeremy?

Pragyan takes fruits, vegetables, bread and egg curry in a day's menu.While his teacher was giving a lecture on trophic level, he got fascinated and asked following questions from his teacher.
(i) How many trophic levels does he occupy in different food chains?
(ii) Represent atleast three food chains.
(iii) Which among them gives him the maximum amount of energy? Give reason.
(iv) What values are shown by Pragyan?