Which of the following groups contain only biodegradable items?

1

(a)

Grass, flowers and leather

(b)

Grass, wood and plastic

(c)

Fruit-peels, cake and lime-juice

(d)

Cake, wood and grass

Which of the following constitute a food-chain?

1

(a)

Grass, wheat and mango

(b)

Grass, goat and human

(c)

Goat, cow and elephant

(d)

Grass, fish and goat

Which of the following are environment-friendly practices?

1

(a)

Carrying cloth-bags to put purchases in while shopping

(b)

Switching off unnecessary lights and fans

(c)

Walking to school instead of getting your mother to drop you on her scooter

(d)

All of the above

An ecosystem includes

1

(a)

All living organisms

(b)

Non-living objects

(c)

Both living organisms and non-living objects

(d)

Sometimes living organisms and sometimes non-living objects

Accumulation of non-biodegradable pesticides in the food chain in increasing amount at each higher trophic level is known as

1

(a)

eutrophication

(b)

pollution

(c)

biomagnification

(d)

accumulation

In an ecosystem, the 10% of energy available for transfer from one trophic level to the next is in the form of

1

(a)

Heat energy

(b)

Light energy

(c)

Chemical energy

(d)

Mechanical energy

Organisms of a higher trophic level which feed on several types of organisms belonging to a lower trophic level constitute the

1

(a)

Food web

(b)

Ecological pyramid

(c)

Ecosystem

(d)

Food chain

Which of the following limits the numbers of trophic levels in a food chain?

1

(a)

Decrease in energy at higher trophic levels

(b)

Deficient food supply

(c)

Polluted air

(d)

Water

Which of the statement is incorrect?

1

(a)

All green plants and blue green algae are producers

(b)

Green plants get their food from organic compounds

(c)

Producers prepare their own food from inorganic compounds

(d)

Plants convert solar energy into chemical energy

The percentage of solar radiation absorbed by all the green plants for the process of photosynthesis is about

1

(a)

1 %

(b)

5 %

(c)

8 %

(d)

10 %

How can you help in reducing the problem of waste disposal? Give any two methods.

2

(a)

Write the common food chain of a pond ecosystem.

2

(a)

We do not clean ponds or lakes, but an aquarium needs to be cleaned. Why?

2

(a)

Comment on "Green plants are called producers".

2

(a)

If a harmful chemical enters a food chain consisting of snacks, grasshoppers, plants and frogs, which one of the organisms is likely to have a maximum concentration of harmful chemicals in its body?

2

(a)

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

5

(a)

What are decomposers? List two consequences of their absence in an ecosystem?

5

(a)

Suggest any four activities in daily life which are eco-friendly.

5

(a)

Give two differences between food chain and food web.

5

(a)

What are the by-products of fertiliser industries? How do they affect the environment?

5

(a)

Explain some harmful effects of agricultural practices on the environment.

5

(a)