NCTB Class 7 Science Chapter 13 “Environment and Pollution” Solution
Bangladesh Board Class 7 Science Solution Chapter 13 “Environment and Pollution” Solution Exercises Question and Answer by Experienced Teacher.
NCTB Solution Class 7 Chapter 13“Change in Surrounding and Various Incidents”
NCTB Bangladesh Board
“Environment and Pollution”
Fill in the blanks:-
(1) To increase cultivable land build up houses, peoples cut ——-.
(2) ——- of industries responsible for water pollution.
Short answered questions:
(1) Give an example how pollution happen.
Answer:- For the increased human population, beside food and shelter, a large number of other materials are needed. So they build up various industries. Wastes from these industries pollute environment.
(2) What can you do take everybody of your area aware to prevent pollution?
Answer:- I can discuss with every body of my are about the harmful effects of pollution and the process of conservation of environment to make the aware.
(3)What should you do to conserve the environment of your home?
Answer:- I should plant trees around my home, throw the household garbage and food remains to a particular place and burn them under the soil to conserve the environment of my home.
(4) What role can you play in the conservation of your school?
Answer:- I can plant trees around my school, throw garbage and food remains to a particular place and i can made every students aware of conservation of environment.
(5) Mention two impacts of water pollution.
Answer:- The two impacts of water pollution are —
(a) For water pollution, fish and other aquatic organism cannot survive in polluted water.
(b) Drinking such polluted water people suffer from diseases like dysentery, diarrhoea, jaundices, typhoid etc.
(6) Why is air pollution harmful for human beings?
Answer:- Air pollution is harmful for human beings. When the quantity of carbon monoxide increases in the air, it mat cause diseases right from breathing problem to fatal diseases like cancer.
Multiple choice questions:-
(1) From which on is water supplied to the residential houses in urban areas?
Answer:- (c) Tube well.
(2) Causes of soil pollution are –
Answer:- (d) (i), (ii) and (iii).
Observe the scene and answer question no. 3 and 4:
(3) Which one is absent in part W of the imaginary scene?
Answer:- (a) Carbon dioxide.
(4) If the occurrence represented in the scene happens on earth-
Answer:- (d) (i) , (ii) and (iii).
(1) (a) What is acid rain?
Answer:- When smoke from industrial plants are released and mixed with air then acid rain occurs.
(1) (b) Why is plastic harmful for soil? Explain.
Answer:- Plastic is harmful for soil because plastic does not easily mix up with soil. So as a result, the fertility of soil is lost and it also hamper normal growth of plants.
(1) (c) What are the problems faced by the balance the environment as shown in the stem?
Answer:- Due to shown in the stem water is pollution and in polluted water fish and other aquatic organisms cannot survive, as a result, balance of the aquatic environment is disturbed.
(2) (a) What is pollution?
Answer:- Nature or human activities or their combined effect may bring in the constituents of the environment and the environmental balance is lost, this called pollution.
(2) (b) Why is water pollution harmful?
Answer:- Water pollution is harmful because drinking polluted water people suffer from diseases like dysentery; etc, fishes and other aquatic organisms cannot survive in polluted, as a result, balance of the aquatic environment is disturbed.
(2) (c) What problem will p of the stem create? Explain.
Answer:- P of the stem will create air pollution. Because p contains carbon monoxide, carbon particles and carbon dioxide which has detrimental effect to the environment.
(2) (d) What sort of contribution can we do to solve the problems created by the stem? Explain with reasons.
Answer:- To solve the problems created by the stem we can treated ‘P’ to make them pollution free before releasing to the environment because it creates air pollution and due to polluted we may suffer from fatal diseases.