Indicate the flow of energy in an ecosystem. Why is it unidirectional? Justify.

List two biotic components of a biosphere.

Explain how do decomposers help is recycling of materials in the ecosystem.

Explain some harmful effects of agricultural practices on the environment.

A food chain comprises of cat, seed-eating bird, plants, and dog. The organism which will have the maximum concentration of harmful pesticides coming through the food chain is most likely to be:

An aquatic food chain comprises of the organisms like tadpoles, weeds, fish and water beetles. The organism which gets the minimum energy through this food chain is:

The surface of water in a lake appears green due to a layer of tiny free-floating organisms X on its surface. The lake water also contains organisms like water beetle, fish and tadpole. The sun shines over the lake water and provides energy for the functioning of this lake ecosystem.

(a) What could organisms X be?

(b) Write a food chain comprising of all the four organisms mentioned.

(c) What is the general name of the food chains like the one written above?

(d) Name

(i) Secondary consumer

(ii) Producer

(iii) Tertiary consumer, and

(iv) Primary consumer in the above food chain

(e) If the tertiary consumer gets 0.2 J of energy from the secondary consumer, then how much energy was radiated by the sun to the producer?

A forest ecosystem having a lot of green plants has some foxes, lions and rabbits in it.

(a) Write a food chain comprising all the four organisms mentioned above.

(b) Name

(i) one herbivore, and

(ii) two carnivores, in this food chain.

(c) Name the link which is a predator as well as a prey.

(d) Name

(i) second trophic level, and

(ii) third trophic level.

(e) Which link of this food chain can feed on second trophic level as well as third trophic level, independently?

(f) If the sun provides 1000 J of energy to the plants, then how much energy will be transferred to fox through the food chain.

A food chain consists of fish, larvae, phytoplankton and birds. The level of pesticides in water in which the fish, larvae and phytoplankton live is quite high.

(a) In which organisms the pesticides enter from the polluted water? What is this level of organisms known as?

(b) Which organism will have the maximum amount of pesticides accumulated through the food chain? What is this process known as?

(c) Write the food chain comprising all the organisms mentioned above.

(d) Which other organism you could write in place of bird in the above food chain?

What are the by-products of fertilizer industries. How do they affect the environment.

Suggest suitable mechanism (s) for waste management in fertilizer industries.