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.

The gas A is used by most of the animals to obtain energy from food by the process of respiration. When A is acted upon by radiation X, it gets converted into another gas B which is an allotrope of A but poisonous when inhaled. B forms a kind of layer C in the upper atmosphere which absorbs radiations X coming from a source Y and prevents them from reaching the earth. Some chemicals Z released from the various devices on the earth are destroying the layer C slowly. In fact, a hole has already been formed in layer Cover the area D of the earth.

(a) What are gases?

(i) A, and

(ii) B? Write their molecular formulae.

(b) Name the layer C.

(c) What are (i) X, (ii) Y, and (iii) Z?

(d) Name the area D.

(e) Name any two human ailments which may be caused by X.

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 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?

Every household produces a lot of material A daily. In one of the methods of disposal B, material A is burned at a very high temperature of about 1000°C in a structure called C. During this process, the organic matter present is removed as D and E whereas F is left behind (which can be dumped in a landfill site).

(a) What is material A

(b) Name the method of disposal B.

(c) What is structure C known as?

(d) What are

(i) D

(ii) E, and

(iii) F?

(e) This method is especially suitable for the disposal of materials produced by certain institution. Name such institutions.