ALLEN Coaching
ApplyRegister for ALLEN Scholarship Test & get up to 90% Scholarship
Search Colleges, Exams, Schools & more
NCERT Solutions for Class 7 Science Chapter 6 Respiration in Organisms
Edited By Irshad Anwar | Updated on Apr 21, 2025 11:32 AM IST
NCERT Solutions for Class 7 Science Chapter 6 Reproduction in Organisms explains how living organisms reproduce to propagate their kind. In animals, reproduction takes place through two modes: asexual reproduction, in which one parent gives rise to offspring that are all alike, and sexual reproduction, in which a male and female gamete fuse to give a new organism. In plants, reproduction takes place through seeds, spores, and vegetative propagation, making them survive and spread. NCERT Solutions for Class 7 also discusses all the basic modes of respiration.
This Story also Contains
- Solved Exercise Questions of NCERT Solutions for Class 7 Science Chapter 6:
- Overview of Chapter 6: Respiration in organisms
- Important Topics of Chapter 6: Respiration in organisms
- NCERT Solutions for Class 7 Science Chapter-Wise
- Practice Questions on Respiration in Organisms
NCERT Solutions for Class 7 also discusses interesting facts such as how bacteria increase in number at a very fast rate through binary fission and how plants such as Bryophyllum produce new plants from their leaves. The chapter provides textbook questions with simple, easy-to-understand answers and enables students to understand topics such as the reproductive system of animals, pollination in plants, and their importance. Such solutions should be prepared for examination and to develop a clear idea of the concepts. Check out NCERT Solutions for other chapters.
Download PDF of NCERT Solutions for Class 7 Science Chapter 6: Download PDF
Solved Exercise Questions of NCERT Solutions for Class 7 Science Chapter 6:
The solutions are given in sequence as per the NCERT textbook data:
Q1. Why does an athlete breathe faster and deeper than usual after finishing the race?
Answer:
The muscles of an athlete undergo anaerobic respiration which means the oxygen is used up faster than being supplied by the blood.
Thus, to inhale more oxygen, an athlete breathes faster and deeper than usual after finishing the race.
Q2. List the similarities and differences between aerobic and anaerobic respiration.
Answer:
The similarities between aerobic and anaerobic respiration are:
(i) Carbon dioxide is produced in both reactions.
(ii) Energy is released in both reactions.
The differences between aerobic and anaerobic respiration are:
| Aerobic | Anaerobic |
| Takes place in the presence of oxygen | Takes place without oxygen |
| Complete breakdown of food | Partial breakdown of food |
| Carbon dioxide and water as the end product | Ethanol, carbon dioxide as the end product(in yeast) |
| Produces more energy | Produces less energy |
Q3. Why do we often sneeze when we inhale a lot of dust-laden air?
Answer:
Sneezing removes the foreign particle like dust particles, smoke from the air inhaled which ensures good air quality inside our body.
When we inhale, unwanted particles get trapped in the hair present in our nasal cavity. However, sometimes these particles may get past the hair causing irritation in the lining of the cavity. This causes sneezing.
Class 7 Science Chapter 10 NCERT Solutions:
Answer:
We know,
Snail will inhale oxygen and exhale carbon dioxide whereas the plant will inhale carbon dioxide for respiration.
The test with snail and without plant will have maximum carbon dioxide concentration. Therefore, the order of test tube containing CO2 is A>C>B .
Hence, test-tube A will have the highest concentration of CO2 .
Q5. Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs
(ii) gills
(iii) spiracles
(iv) skin
Answer:
A cockroach has small openings called spiracles on the sides of its body.
Therefore, (a) In cockroaches, air enters the body through (iii) spiracles
(i) carbon dioxide
(ii) lactic acid
(iii) alcohol
(iv) water
Answer:
(b) During heavy exercise, we get cramps in the legs due to the accumulation of (ii) lactic acid
During heavy exercise, muscle cells respire anaerobically because oxygen is used faster as compared to its supply by the blood. The partial breakdown of glucose produces lactic acid whose accumulation causes muscle cramps.
Q5. Tick the correct answer:
(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:
The normal range of breathing rate per minute in an average adult person at rest is (ii) 15–18
This means on average, an adult human being breathes in and out 15–18 times in a minute.
Q5. Tick the correct answer:
(d) During exhalation, the ribs
(i) move outwards
(ii) move downwards
(iii) move upwards
(iv) do not move at all
Answer:
During exhalation, the ribs (ii) move downwards
During exhalation, ribs move down and inwards reducing the size of the chest cavity causing the air to be pushed out of the lungs.
Q6. 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
Answer:
| 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 |
Q7. 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)
Answer:
(i) During heavy exercise the breathing rate of a person slows down. False
- During heavy exercise, we breathe faster and deeper than usual
(ii) Plants carry out photosynthesis only during the day and respiration only at night. False
- Respiration is an essential process required for the plants to live. It occurs day and night. Whereas, photosynthesis takes place only during the day.
(iii) Frogs breathe through their skins as well as their lungs. True
(iv) The fishes have lungs for respiration. False
- Fishes do not have lungs. They breathe through gills.
(v) The size of the chest cavity increases during inhalation. True
- During inhalation, ribs move up and outwards and the diaphragm moves down. This movement increases space in our chest cavity and air rushes into the lungs.
(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
Answer:
(i) The air tubes of insects - TRACHEA
(ii) Skeletal structures surrounding chest cavity - RIBS
(iii) Muscular floor of chest cavity - DIAPHRAGM
(iv) Tiny pores on the surface of leaf - STOMATA
(v) Small openings on the sides of the body of an insect - SPIRACLES
(vi) The respiratory organs of human beings - LUNGS
(vii) The openings through which we inhale - NOSTRILS
(viii) An anaerobic organism - YEAST
(ix) An organism with tracheal system - ANT
Q9. 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.
Answer:
The mountaineers carry oxygen with them because the amount of oxygen available to a person is less than that available on the ground.
Hence, the correct answer is option (b)
As we move higher in altitude, the density of the atmosphere lessens.
NCERT Solutions for Class 7- Subject Wise
Overview of Chapter 6: Respiration in organisms
This chapter discusses that living organisms digest food to free energy needed for their physiological processes. The respiratory system in animals is the most vital; the lungs (or respiratory organs) assist in the uptake of oxygen, which is utilized in the digestion of food to be used for energy, and carbon dioxide is expelled as a byproduct. In plants, gaseous exchange occurs across the surface of stomata and lenticels, maintaining a constant supply of oxygen and removal of carbon dioxide. Processes such as exhalation in animals and diffusion of gases in plants are efficient means of disposing of wastes without interrupting balance in the body of the organism.
Important Topics of Chapter 6: Respiration in organisms
Topics and Sub-Topics in Chapter 6 Respiration in Animals and Plants:
| Section | Topic Name |
| 10 | Respiration in Organisms |
| 10.1 | Why do we respire? |
| 10.2 | Breathing |
| 10.3 | How do we Breathe? |
| 10.4 | What do we breathe out? |
| 10.5 | Breathing in Other Animals |
| 10.6 | Breathing underwater |
| 10.7 | Do plants also respire? |
NCERT Solutions for Class 7 Science Chapter-Wise
The chapterwise solutions are given below:
Practice Questions on Respiration in Organisms
Question: What is respiration in organisms?
Answer: Respiration is a biochemical process through which organisms produce energy from food, particularly glucose. This energy is required to perform different life processes such as growth, repair, and movement.
Question: What are the types of respiration?
Answer: There are two types of respiration:
Aerobic respiration takes place in the presence of oxygen and yields more energy.
Anaerobic respiration is done without oxygen and yields lower amounts of energy.
Question: What organisms undertake anaerobic respiration?
Answer: Anaerobic respiration is largely practiced by a few microorganisms such as yeast and some bacteria. In man, it might happen in muscles under strenuous exercise when the body lacks adequate oxygen.
Question: Write a chemical equation for aerobic respiration.
Answer: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)
Glucose and oxygen combine to yield carbon dioxide, water, and energy.
Question: Why does respiration differ from breathing?
Answer:
Breathing is a physical process of inhalation and exhalation of air.
Respiration is a chemical process occurring in cells to release energy.
Question: Match the following:
A. Aerobic respiration – i. Without oxygen
B. Anaerobic respiration – ii. With Oxygen
C. ATP – iii. The energy currency of the cell
Options:
A-ii, B-i, C-iii
A-i, B-ii, C-iii
A-iii, B-ii, C-i
A-ii, B-iii, C-i
Answer: Option 1: A-ii, B-i, C-iii
Question: Explain the function of mitochondria in cellular respiration. Why is it referred to as the powerhouse of the cell?
Answer: Mitochondria are unique organelles present in eukaryotic cells that are responsible for energy production via aerobic respiration. Mitochondria are also described as the "powerhouse of the cell" since they produce most of the ATP, the main energy currency used for the majority of cellular processes.
Role in Respiration
Glycolysis: Although glycolysis is in the cytoplasm, the subsequent steps of aerobic respiration (Krebs cycle and electron transport chain) occur in the mitochondria.
Krebs Cycle: Pyruvate (formed from glucose) is broken down into carbon dioxide and high-energy molecules (NADH, FADH₂) in the matrix of the mitochondria.
Electron Transport Chain: This process is in the inner mitochondrial membrane. Oxygen is utilized as the terminal electron acceptor, and ATP is produced through oxidative phosphorylation. Mitochondria are essential since they supply the energy cells require to carry out fundamental processes like protein synthesis, transport, and cell division. If cells lacked effective energy production in mitochondria, they would not be able to live.
Question: What are the similarities and differences between plant and animal respiration?
Answer: Both animals and plants respire to release energy from glucose. The process and function of respiration in animals and plants differ, though.
Similarities:
Both plants and animals respire to produce energy (ATP) for the process of life. Oxygen is utilized in the process of aerobic respiration in both animals and plants, and the byproduct is carbon dioxide. Both are the processes of breaking glucose into ATP via the same steps (glycolysis, Krebs cycle, and electron transport chain).
Differences:
Location: Respiration in animals takes place within the mitochondria of all cells, whereas in plants, respiration takes place within all living cells, but a related process of photosynthesis takes place primarily in chloroplasts of leaves.
Oxygen Utilization and Carbon Dioxide Exhalation: Animals alone use oxygen and exhale carbon dioxide, while plants utilize oxygen and exhale carbon dioxide during the night when there is no photosynthesis. Plants do photosynthesis during the daytime, taking in carbon dioxide and exhaling oxygen, so they differ from animals in that way.
Production of Energy: Plants generally use respiration to yield usable ATP from stored energy contained in sugars but also use sunlight energy through the process of photosynthesis. Animals, however, entirely rely upon respiration in order to extract energy from sources of food.
Also, Check NCERT Books and NCERT Syllabus here
We hope you will ace your examination with the help of NCERT Solutions for Class 7 Science Chapter 6 Respiration in Organisms.
Frequently Asked Questions (FAQs)
1. Is the Class 7 Science Chapter 10 Respiration in Organisms is useful in higher studies ?
Yes, this chapter is very important for higher studies in the field of science and Biology. Respiration in Organisms will be studied in NCERT Class 10 .
2. What is respiration class 7?
All living things generate the energy they need to survive through the process of respiration. Since this takes place within the cells, it is also known as cellular respiration. Normally, two gases—oxygen and carbon dioxide—are exchanged. The cells absorb oxygen and expel carbon dioxide.
3. How many questions in NCERT solutions for class 7 science chapter 10?
There are 9 questions in NCERT solution class 7 science chapter 6.
4. How does respiration take place in humans?
Respiration in humans starts when we take oxygen-rich air into the lungs. Oxygen seeps into the blood and gets distributed to cells, where it assists in decomposing glucose in order to liberate energy. Carbon dioxide is a by-product that gets transferred back to lungs and expelled out.
5. Why is oxygen necessary for respiration?
Oxygen is required for respiration, as it assists in breaking down glucose to generate energy. This is achieved during aerobic respiration within the mitochondria of cells. Cells generate less energy when they lack oxygen and use anaerobic respiration.
6. How does respiration occur in plants?
Plant respiration takes place in every cell, where glucose is fermented with oxygen to release energy. This process mainly occurs in the mitochondria. The energy thus generated maintains growth, repair, and other important functions.
7. How do fish breathe in water?
Fish breathe through water by sucking it in through their mouth and letting it flow over their gills. Gills remove dissolved oxygen from the water and give out carbon dioxide. The oxygen flows into the fish's bloodstream to sustain basic functions.
8. What are the effects of anaerobic respiration in muscles?
Anaerobic respiration in muscles yields energy without the use of oxygen and results in the creation of lactic acid. This accumulation results in muscle fatigue and soreness. It yields rapid energy during hard work but is not as effective as aerobic respiration.
9. Do all living organisms have the same type of respiration process?
No, all living things do not share the same kind of respiration process. Some utilize aerobic respiration with oxygen, while others utilize anaerobic respiration without oxygen. The kind varies depending on the organism and its surroundings.
10. What is respiration?
Respiration is the mechanism through which living things liberate energy from food. It most commonly involves the breakdown of glucose in the presence of oxygen. This energy is utilized for a number of activities of life such as growth, movement, and repair.
Also Read
Articles
Apr 26, 2025
Popular Questions
A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is
| Option 1)
|
Option 2)
|
| Option 3)
|
Option 4)
|
An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range
| Option 1)
|
Option 2)
|
| Option 3)
|
Option 4)
|
A particle is projected at 600 to the horizontal with a kinetic energy . The kinetic energy at the highest point
| Option 1)
|
Option 2)
|
| Option 3)
|
Option 4)
|
In the reaction,
| Option 1)
|
Option 2)
|
| Option 3)
|
Option 4)
|
How many moles of magnesium phosphate, will contain 0.25 mole of oxygen atoms?
| Option 1)
0.02 |
Option 2)
3.125 × 10-2 |
| Option 3)
1.25 × 10-2 |
Option 4)
2.5 × 10-2 |
Colleges After 12th
Popular Course After 12th
Study Resources, Applications and Opportunities
NEET/JEE Coaching Scholarship
ApplyGet up to 90% Scholarship on Offline NEET/JEE coaching from top Institutes
NEET Most scoring concepts
Get nowThis ebook serves as a valuable study guide for NEET 2025 exam.
NEET Previous 10 Year Questions
Get nowThis e-book offers NEET PYQ and serves as an indispensable NEET study material.
JEE Main Important Physics formulas
Get nowAs per latest 2024 syllabus. Physics formulas, equations, & laws of class 11 & 12th chapters
JEE Main Important Chemistry formulas
Get nowAs per latest 2024 syllabus. Chemistry formulas, equations, & laws of class 11 & 12th chapters
News and Notifications
Ask
Question
Student Community: Where Questions Find Answers
Back to top