NCERT Solutions for Class 7 Science: Chapter 10 - Respiration in Organisms

Get NCERT Solutions for Class 7 Science: Chapter 10 - Respiration in Organisms. With this article, you can also access Chapter 10 of Class 7 Science NCERT Textbook (latest edition).

Jul 5, 2019 08:07 IST
NCERT Solutions for Class 7 Science: Chapter 10 - Respiration in Organisms

NCERT Solutions for Class 7 Science: Chapter 10 - Respiration in Organisms is available here. You can also download Chapter 10 - Respiration in Organisms of Class 7 Science NCERT Textbook with the help of download link, given at the end of this article.

NCERT Solutions for Class 7 Science: Chapter 10 - Respiration in Organisms

1. Why does an athlete breathe faster and deeper than usual after finishing the race?


An athlete consumes a lot of energy during running which is produced by oxidation of glucose. By breathing deeper and faster, the athlete is basically consuming more and more oxygen to meet his or her energy requirements.

2. List the similarities and differences between aerobic and anaerobic respiration.


Aerobic Respiration

Anaerobic Respiration

It happens in the presence of oxygen.

It happens in the absence of oxygen.

Main products are CO2 and H2O

The end products can be CO2,Lactic acid and alcohol.

Large amount of energy is produced.

Small amount of energy is produced as compared to aerobic respiration.

3. Why do we often sneeze when we inhale a lot of dust-laden air?


By sneezing, our body tries to expel the dust particles from the air we inhaled so that only clean air enters our body.

4. Take three test-tubes. Fill ¾th of each with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2?


The concentration of CO2 will be highest in test-tube A because snail takes oxygen and breathes out carbon dioxide. Whereas, plants take CO2 and produce oxygen. 

5. Tick the correct answer:

(a) In cockroaches, air enters the body through

(i) lungs

(ii) gills

(iii) spiracles

(iv) skin

Solution5 (a):

Option (i) is correct.

(b) During heavy exercise, we get cramps in the legs due to the accumulation of

(i) carbon dioxide

(ii) lactic acid

(iii) alcohol

(iv) water

Solution 5 (b):

Option (ii) is correct.

(c) Normal range of breathing rate per minute in an average adult

person at rest is:

(i) 9–12

(ii) 15–18

(iii) 21–24

(iv) 30–33

Solution 5 (c):

Option (ii) is correct.

(d) During exhalation, the ribs

(i) move outwards

(ii) move downwards

(iii) move upwards

(iv) do not move at all

Solution 5 (d):

Option (ii) is correct.

6. Match the items in Column I with those in Column II:

Column I Column II

(a) Yeast           (i) Earthworm

(b) Diaphragm  (ii) Gills

(c) Skin              (iii) Alcohol

(d) Leaves         (iv) Chest cavity

(e) Fish               (v) Stomata

(f) Frog               (vi) Lungs and skin

                            (vii) Tracheae

Solution 6:

Column I       Column II

(a)Yeast       (iii) Alcohol

(b)Diaphragm (iv) Chest cavity

(c) Skin         (i) Earthworm

(d) Leaves     (v) Stomata

(e) Fish         (ii) Gills

(f) Frog         (vi) Lungs and skin

7.Mark ‘T’ if the statement is true and ‘F’ if it is false:

(i) During heavy exercise the breathing rate of a person slows down. (T/F)



(ii) Plants carry out photosynthesis only during the day and respiration only at night. (T/F)



(iii) Frogs breathe through their skins as well as their lungs. (T/F)



(iv) The fishes have lungs for respiration. (T/F)



(v) The size of the chest cavity increases during inhalation. (T/F)



8. Given below is a square of letters in which are hidden different words related to respiration in organisms. These words may be present in any direction— upwards, downwards, or along the diagonals. Find the words for your respiratory system. Clues about those words are given below the square.

 (i) The air tubes of insects

(ii) Skeletal structures surrounding chest cavity

(iii) Muscular floor of chest cavity

(iv) Tiny pores on the surface of leaf

(v) Small openings on the sides of the body of an insect

(vi) The respiratory organs of human beings

(vii) The openings through which we inhale

(viii) An anaerobic organism

(ix) An organism with tracheal system

Solution 8:

9. The mountaineers carry oxygen with them because:

(a) At an altitude of more than 5 km there is no air.

(b) The amount of air available to a person is less than that available on the ground.

(c) The temperature of air is higher than that on the ground.

(d) The pressure of air is higher than that on the ground.

Solution 9:

Option (b) is correct.