Which of the following cannot be added in a composting pit to prepare compost?

The harmful chemical which is accumulating in human beings through food chain is:

O₂ is converted into O₃ by the action of:

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?