Which of the following compound is not degraded by any biological process?

1

(a)

CFCs

(b)

CH₄

(c)

Glucose

(d)

Nitrites

The surface of the earth covered with water is 

1

(a)

75%

(b)

50%

(c)

25%

(d)

10%

Bits of decayed living organisms in soil is called

1

(a)

decomposer

(b)

humus

(c)

saprob

(d)

compost

Which one of the following are not involved in nitrogen fixation?

1

(a)

Free living bacteria

(b)

Rhizobium

(c)

Lightning

(d)

Parasitic bacteria

Nitrogen fixing bacteria cannot fix N₂ in presence of 

1

(a)

CO₂

(b)

N₂

(c)

O₂

(d)

light

We need to ........ our natural resources and use them in a .......... manner.

1

(a)

conserve, sustainable

Various man-made compounds such as ........ cause depletion of ozone layer.

1

(a)

CFCs

Increase in concentration of carbon dioxide in the atmosphere may cause ........ effect.

1

(a)

greenhouse

The nitrogen-fixing bacteria found in the roots of legumes in special structures called as root .........

1

(a)

nodules

The combustion of fossil fuels increases the amount of ........ .......... in air.

1

(a)

suspended particles

Does there exist any relationship between the climate and biotic components? If yes, explain with example.

2

(a)

Name the air pollutants released by industries.

2

(a)

What is soil erosion?

2

(a)

List the main elements/substances of biogeochemical cycles.

2

(a)

Mention a cause and a consequence of acid rain.

2

(a)

Why is replenishment of forests necessary?

5

(a)

What is "greenhouse effect'? What would be its effect? name two greenhouses gases.

5

(a)

Is it necessary to replenish forests?

5

(a)

April 22, is celebrated by countries all over the world as the Earth Day clean Delhi took the initiative and organised Saving the greens campaign.
Equipped with gloves,rakes,gunny, bags and a lot of enthusiasm,students  assembled at a park on the Ridge and took upon themselves the task of cleaning the Ridge. Activities that were carried out included picking up all the polybags that were littering a part of the ridge and removing advertisements nailed to trees.disturbing pamplets at the crossing to passersby In about on hours time the children managed to collect about 20 large gunny bags full of plastic
Answer the following questions based on above information
(a) What are messages sent by their activity to the public of Delhi?
(b) What is your suggestion?
(c) Which values are displayed by the childrean?

5

(a)