Chapter-1 Our Environment

A. Choose the correct answer.

1. This is not a part of the natural environment. 

a. Swimming pool

b. Lake

c. Forest 

d. Soil

Ans. a. Swimming pool

2. The percentage of the Earth surface covered by water is:

a. 81%

b. 71%

c. 97%

d. 24%

Ans. b. 71%

3. The earth is enveloped in a thin layer of air, known as the:

a. Atmosphere

b. Hydrosphere

c. Biosphere

d. Atmos 

Ans. a. Atmosphere 

4. These are not a part of a rotting tree trunk ecosystem: 

a. Mushrooms

b. Snakes

c. Insects

d. Algae

Ans. d. Algae

5. To save our environment, we should:

a. Set up more factories

b. Use our natural resources judiciously

c. Encourage deforestation

d. Dump waste in natural environments 

Ans.c. Encourage deforestation

B. Fill in the blanks.

1. Our environment comprises both ______ and _______ things.

Ans. living, non-living

2. The physical environment consists of the ________ , _________ and _________. 

Ans. Lithosphere, hydrosphere, atmosphere

3. The Greek word 'lithos' means ______.

Ans. stone

4. The biological environment is also known as the _________. 

Ans. biosphere

5. In an ecosystem, everything is closely ________.

Ans. interconnected

C. Answer in one or two sentences. 

1. Define environment.

Ans. The environment is everything that surrounds us - such as plants, animals, land, houses, factories and roads. 

2. What is the lithosphere?

Ans. The hard, outermost layer of the earth is known as lithosphere. 

3. What is the function of the atmosphere in the environment?

Ans. The function of the atmosphere in the environment is to provide living organisms with the life-supporting gases, the atmosphere also helps control the temperature on the Earth. 

4. What is the biosphere?

Ans. The biological environment , or the biosphere, is a narrow zone where the lithosphere, the hydrosphere and the atmosphere come into contact with each other.

5. What is the socio-cultural environment?

Ans. The socio-cultural environment consists of family, religion, education, the customs and the beliefs of the people who live in an area. 

6. Name two factors that have contributed environmental degradation.

Ans. Widespread deforestation and pollution have led to many environmental problems like global warming, destruction of ecosystem and the extinction of animals.