General Science 5th Class Chapter 4 Environmental Pollution Solved Exercise

General Science

5th Class

Chapter 4

Environmental Pollution

Questions

1. Encircle the correct option.

i. Which disease is caused due to air pollution?

a. Diarrhea        b. Typhoid        c. lung cancer        d. Cholera

ii. The germs present in it cause typhoid.

a. Sewerage water        b. Fertilizers        c. Factory waste        d. Insecticides

iii. Which one of these is non-biodegradable?

a. Feathers        b. Paper        c. Leaves of plants        d. Polythene bag

iv. Which of the following is NOT a greenhouse gas?

a. Oxygen        b. Methane        c. Ozone        d. Carbon dioxide

v. Which one of the following acts causes most of the air pollution?

a. Collecting rubber        b. Burning rubber

c. Reusing rubber        d. Recycling rubber

2. Write short answers.

i. Write three causes of air pollution.

Ans.

1.  Smoke emitted from vehicles and factories pollute air.

2. The burning of fuels in the kilns and homes produces carbon dioxide gas which pollutes the air.

3. The fire in the forests also causes air pollution.

ii. What are the four effects of pollution on life?

Ans.

1. Germs present in pollutes water are cause of the diseases.

2. Bacteria present in sewerage use most of the dissolved oxygen present in water. The aquatic animals e.g. fish die due to lack of oxygen.

3. Pollutant gases present in smog cause lungs diseases and allergy.

4. Poisonous substances and gases are produced by open garbage dumps. These substances cause air and water pollution.

iii. What is greenhouse effect?

Ans. Green house effect is a natural process. That warms the earth surface when sun energy reaches the earth atmosphere some of it reflected back and the rest is absorbed. Due to this earth atmosphere is getting hot.

iv. What will be the effects of global warming?

Ans.

The climate of the world is changing due to global warming. Therefore, the sea level is rising due to melting of ice on poles of earth. It is causing more rains and floods. If this process continues, the coastal and islands may disappear in the sea.

v. Write three ways of preventive measures to reduce pollution.

Ans.

1. We should use public transport instead of personal vehicles.

2. Cutting of trees and forests should be reduced.

3. There should be more tree plantation.

3. Constructed Response Questions:

i. What is the main cause of pollution?

Ans. Following are the main causes of pollution:

• Garbage
• Wastes of factories
• Agriculture waste
• Smoke from vehicles
• Over population

ii. Why Government of Pakistan has banned the use of polythene bags?

Ans. Government of Pakistan has banned the use of polythene bag because they are non biodegradable substances and can not dissolve in environment. That is main cause of pollution.

iii. If it is written D2W on the polythene bags then why there is no ban on the use of such bags?

Ans. The polythene bag that is written with D2W are banned because they can dissolve after sometime in environment.

4. Investigate:

i. What is the relationship between diseases and pollution?

Ans. The main reason of disease spreading is pollution. Where there is more pollution, there will be more diseases.

ii. Identify biodegradable and non-biodegradable materials present in your environment. 

Ans. 

Biodegradable Materials	Non-Biodegradable Materials
Wood, Paper, Cloth, Peels fruits and vegetables	Glass pieces, polythene bag leather

5. Project:

Preparing Organic fertilizer

Material Required:

1. Plastic bucket
2. Peels of vegetables, fruits and egg shells
3. Grass
4. Dry leaves
5. Water
6. Wooden rod

Procedure:

1. In a small plastic bucket put peels of vegetables, fruits, egg shells, dry leaves and some grass
2. Pour water so that all of these become wet.
3. Stir with the help of a wooden rod that these can get oxygen.
4. When these things become brown it means the fertilizer has been made. It is called organic fertilizer. Now you can use it for plants.