NCERT Solutions Science Chapter 10 Respiration in Organisms for Class 7th
In Chapter 10 of Class 7 Science, titled “Respiration in Organisms,” we learn about the process of respiration, its importance, and the different ways organisms respire.
Definition of Respiration: Respiration is the biochemical process by which living organisms convert food into energy. This process is essential for growth, repair, and daily activities.
Types of Respiration: 1. Aerobic Respiration: This type requires oxygen. It takes place in most plants and animals, producing energy, carbon dioxide, and water as byproducts.
2.Anaerobic Respiration: This occurs in the absence of oxygen. It is less efficient and is used by some microorganisms and during intense exercise in animals. It produces energy along with byproducts like alcohol or lactic acid.
Respiration in Different Organisms:
Plants: They mainly respire during the night since photosynthesis (which produces oxygen) occurs during the day. Plants take in oxygen and release carbon dioxide.
Animals: Most animals, including humans, use lungs for respiration, exchanging oxygen and carbon dioxide through breathing.
Microorganisms: Bacteria and fungi can respire both aerobically and anaerobically, depending on their environment.
The Importance of Respiration:
Respiration provides energy needed for vital processes like growth, reproduction, and movement.
It also helps in maintaining body temperature and supporting metabolic activities.
Respiration vs. Breathing:
Breathing is a physical process of inhaling oxygen and exhaling carbon dioxide, while respiration is a chemical process that takes place in the cells to produce energy.
NCERT Solutions Science Chapter 10 Respiration in Organisms for 2024-2025
Q1. Why does an athlete breathe faster and deeper than usual after finishing the race?
Answer:
During the run, the demand of energy is high but the supply of oxygen to produce energy is limited. Therefore, anaerobic respiration takes places in the muscle cells to fulfill the demand of energy. After finishing the race, an athlete breathe faster and deeper than usual so that more oxygen is supplied to the cells.
Q2. List the similarities and differences between aerobic and anaerobic respiration.
Answer:
Similarity:
(i) In both aerobic and anaerobic respiration, food is broken down to release energy.
(ii) Both takes place inside cells.
(iii) Both produces byproducts.
Differences:
| Aerobic Respiration | Anaerobic Respiration |
| (i) It takes place in the presence of oxygen. | (i) It takes place in the absence of oxygen. |
| (ii) Energy is released in higher amount. | (ii) Energy is released in lesser amount. |
| (iii) Carbon dioxide and water are produced as byproducts. | (iii) Carbon dioxide and water are produced as byproducts. |
| (iv) It is a slow process. | (iv) It is a fast process. |
| (v) Examples: Animals and plants cells. | (iv) Examples: Human cells, yeast, Bacteria etc. |
Q3. Why do we often sneeze when we inhale a lot of dust-laden air?
Answer:
We often sneeze when we inhale a lot of dust-laden air to expel out these foreign particles. These particles get past the hair in the nasal cavity and irritate the lining of the cavity which results in sneezing.
Q4. Take three test-tubes. Fill each of them 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 ?
Answer:
Test-tube A will have the highest concentration of CO2 because snail will take in oxygen and gives out CO2.
In test-tubes B and C, the CO2 will be utilized by the water plant for synthesizing food and hence there will be less concentration of CO2 in these.
Q5. Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs
(ii) gills
(iii) spiracles
(iv) skin
Answer: (iii) spiracles
(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
Answer: (ii) lactic acid
(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
Answer: (ii) 15 – 18
(d) During exhalation, the ribs
(i) move outwards
(ii) move downwards
(iii) move upwards
(iv) do not move at all
Answer: (ii) move downwards