NCTB Class 7 Science Chapter 4 Respiration Solution

NCTB Class 7 Science Chapter 4 “Respiration Solution”

Bangladesh Board Class 7 Science Solution Chapter 4 “Respiration” Solution  Exercises Question and Answer by Experienced Teacher.

NCTB Solution Class 7 Chapter 4 “Respiration:”

Board NCTB Bangladesh Board
Class 7
Subject Science
Chapter Four
Chapter Name “Respiration”

Fill in the blanks:-

(1) In—-food is produced but in——food is oxidized.

Ans:- Respiration.

(2) ——-is called the power house of a cell.

Ans:- Mitochondria.

(3) Lung is composed of a large number of—-.


(4) —–Is an infectious disease.

Ans:- Tuberculosis.

(5) Preparation is a—-process.

Ans:- Metabolic.

Short answered questions:-

(1) Ans:- During internal respiration, inside mitochondria within cell oxygen acts on food in some enzyme controlled reactions.

(2) Ans:- The causes of pneumonia are severe cold attack, infection with one type of bacteria. The symptoms of pneumonia are cough, breathing difficulties, high fever with feelings of constant pain in the chest.

(3) Ans:- The necessity of respiration is respiration process produces energy which necessary for performing different physiological activities of living organism.

(4) Ans:-  The function of alveoli is to transport air and carbon dioxide.

(5) Ans:- Plants do not have any definite respiratory organ. So oxygen enters inside plants body through stomata, inter cellular spaces. Animals respire through skin, trachea, lungs, gills etc.

Multiple choice questions:-

(1) Which one is not a respiratory system?

Ans:- (c) Guard cell.

(2) Lower animals respire with the help of-

Ans:- (b) (ii).

(3) What is the name of ‘W’ labelled part?

Ans:- (b) Bronchus.

(4) In which part of the exchange of O and CO occur?

Ans:- (d) Y

(5) Name the disease produced by the infection of part ‘V’

Ans:- (b) Bronchitis.

Creative questions:-

(1) (a)  Ans:- Lungs are covered with two fold membranes which is called pleura.

(1) (a) Ans:– Pneumonia is total disease because due to this disease the patients suffer from cough and breathing problems, constant pain in chest, high fever and the lungs become damaged.

(1) (c) Ans:- According to the diagram, our chest continuously expands and shrinks and takes oxygen and drives out carbon dioxide like balloons. As a result the area of the lungs increases and decreases in volume. Lungs continuously expand and shrink to inhale oxygen and exhale carbon dioxide. This is called breathing.

(1) (d) Ans:- When ‘F’ Substance enters into pare then a problem is created. The remedies of the problem are the patent should live in a well ventilated and well lighted housed house, avoid dust and smoke.

(2) (a) Ans:- Respiration is a metabolic process, in this process, every organism takes oxygen from atmosphere and releases carbon dioxide. This produces energy.

(2) (b) Ans:- Plants do not have any definite respiratory organ. But plants have one kind of pores in leaves called stomata, through which oxygen enters inside the plant body. That’s stomata helps plants in respiration.

(2) (c) Ans:- ‘Y’ utilizes the product of photosynthesis in which ‘Y’ prepare their own food in presence of the product of ‘x’

(2) (d) Ans:- During the photosynthesis ‘Y’ exhales oxygen in the air which ‘Z’ inhale during respiration. Similarly during respiration ‘z’ exhales carbon dioxide in the air which ‘Y’ inhales during photosynthesis This is how ‘Y’ and ‘Z’ are interdependent on each other for gaseous exchange.




Updated: November 20, 2020 — 11:16 am

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