List the different steps and state their role in the process of decomposition in an ecosystem.

5

(a)

Explain the carbon cycle with the help of a simplified model.

5

(a)

'All successions proceed to a similar climax community,the mesic'.Explain.

5

(a)

Describe the components of an ecosystem.

5

(a)

(a) Draw a 'pyramid of numbers' of a situation, where a large population of insects fed upon a very big tree.The insects in turn are eaten by small birds,which in turns are fed upon by birds.

5

(a)

Describe a pond as an ecosystem.

5

(a)

A farmer harvests his crop and expresses his harvest in three different ways:
(a) I have harvested 10 quintals of wheat.
(b) I have harvested 10 quintals of wheat today in one acre land.
(c) I have harvested 10 quintals of wheat in one acre of land, 6 months after sowing.
Do the above statements mean one and the same thing. If your answer is "Yes", give reasons. And if your answer is "No", explain the meaning of each expression.

5

(a)

What will happen to an ecosystem if
(a) All producers are removed.
(b) All organisms of herbivore level are eliminated and
(c) All top carnivore population is removed.

5

(a)

Give two examples of artificial or man-made ecosystems. List the salient features by which they differ from natural ecosystems.

5

(a)

What is meant by sedimentary cycle? Depict diagrammatically the phosphorous cycle or sulphur cycle.

5

(a)