NCERT Solutions for Class 7 Science Chapter 6 Respiration in Organisms

Science is a subject that helps us explore and understand the natural processes happening around and within us. It encourages students to observe, question, and find answers through reasoning and facts. In Class 7 Science, every chapter teaches us of how living things function and survive.

Chapter 6 – Respiration in Organisms, is an essential part of the CBSE Class 7 Science curriculum. This chapter explains one of the most vital processes of life—respiration. It introduces students to how organisms produce energy from food, the role of oxygen, and how different types of respiration take place in various living beings.

NCERT Class 7 Science Chapter 6 – Respiration in Organisms teaches how living things get energy from the food they eat. Students learn about aerobic and anaerobic respiration, how humans and animals breathe, and the importance of oxygen. The NCERT textbook questions cover all important topics and help in building strong concepts. These NCERT Solutions for Class 7 Science solutions also prepare students for the CBSE Class 7 Science exams with accurate and easy-to-understand answers. Studying this chapter helps students connect science with real-life biological processes.

NCERT Solutions for Class 7 Science Chapter 6 Respiration in Organisms 

Chapter 6 – Respiration in Organisms introduces students to one of the most essential life processes: how living beings produce energy from the food they eat. In this chapter, students will learn the difference between breathing and respiration, explore aerobic and anaerobic respiration, and understand how different organisms like humans, insects, fish, and plants carry out respiration.

The chapter also explains the role of oxygen, the respiratory system in humans, and how energy is released in cells. This chapter not only strengthens students’ basic biology knowledge but also helps them connect science with real-life processes happening inside their own bodies.

NCERT Solutions for Class 7 Science Chapter 6 Respiration in Organisms PDF Download 2025-26

To do well in exams, students can download NCERT Solutions for Chapter 6 in PDF format. These solutions are created by the experienced faculty team at Infinity Learn, following the latest CBSE syllabus and exam trends. 

By thoroughly understanding the chapter, our goal is to offer simple, accurate answers to all textbook questions. This helps students understand the concepts clearly and build a strong foundation for their science learning.

 Access Class 7 Science Chapter 7 NCERT Solutions – Respiration in Organisms 

1. Why does an athlete breathe harder and faster after finishing a race?

Answer: When an athlete runs, their muscles use a lot of energy. Energy production happens through the breakdown of glucose, needing lots of oxygen to produce ATP. After the race, the body requires more oxygen to replenish energy stores and remove waste (like carbon dioxide), so the athlete breathes faster and deeper.

2. How are aerobic and anaerobic respiration alike and how do they differ?
Answer:
Similarities:

Both produce energy.

Both release carbon dioxide.

Differences:

Aerobic respiration uses oxygen, while anaerobic respiration does not.

Aerobic respiration fully breaks down glucose, giving more energy; anaerobic respiration only partially breaks it down, giving less energy and producing products like lactic acid or alcohol.

3. Why do we sneeze when we inhale dust or irritants?
Answer:
When dust or other small particles go into the nose, they bother the inside lining, causing sneezing. Sneezing is the body’s natural defense mechanism to quickly expel these particles using a forced burst of air.

4. Experiment: In three test tubes filled with water—
Test Tube A: has a slug.

Test Tube B: has a water plant.

Test Tube C: has both slug and plant.

Which tube will have the highest carbon dioxide level and why?

Answer: Test Tube A will have the most CO₂. The slug continuously breathes and releases carbon dioxide. In Test Tube C, the plant uses some of that CO₂ for respiration during the day, so CO₂ levels won't be as high as in A.

5. Choose the right option for each statement:
a. How do cockroaches breathe?

(i) Lungs

(ii) Gills

(iii) Spiracles

(iv) Skin

Answer: (iii) Spiracles — small openings along their bodies.

b. What causes cramps in muscles during heavy exercise?

(i) Carbon dioxide

(ii) Lactic acid

(iii) Alcohol

(iv) Water
Answer: (ii) Lactic acid — it builds up in muscles and causes cramps.

c. What is the normal breathing rate of an adult when they are resting?

(i) 9–12

(ii) 15–18

(iii) 21–24

(iv) 30–33
Answer: (ii) An adult who is resting usually breathes about 15 to 18 times in one minute.

d. During exhalation, which way do ribs move?

(i) Outward

(ii) Downward

(iii) Upward

(iv) Don’t move
Answer: (ii) Downward

6. True or False:

Rewrite these statements and explain:

Breathing rate slows down during exercise.

False. During exercise, breathing speeds up to meet the higher oxygen demand and remove excess carbon dioxide.

Plants do respiration only at night.

False. Plants photosynthesize during the day, but respiration happens day and night to release energy.

Frogs breathe only through their lungs.

False. Frogs breathe using both their lungs and their wet skin.

Fish use lungs to breathe.

False. Fishes breathe using gills, not lungs.

The chest cavity expands during inhalation.

True. The ribs move up and out, expanding the chest cavity to let air in.

7. Why do mountaineers carry oxygen cylinders?
Answer:
At higher places like mountains, the air has less oxygen because it is thinner, which makes breathing harder. To keep their body functioning properly and prevent altitude sickness, mountaineers carry extra oxygen.

NCERT Solutions for Class 7 Science Chapter 6 Extended Learning — Activities and Projects Answers

1. Observation of Fish Respiration:
When we observe a fish in an aquarium, we see flap-like structures on both sides of its head. These are gill covers that open and close alternately. Fish take in water through their mouth, and this water passes over the gills. Gills absorb oxygen dissolved in water and release carbon dioxide. The oxygen mixes with the blood and reaches every cell in the fish’s body. This is how fish respire using gills.

2. Effects of Smoking and Local Survey:
Smoking has harmful effects on health. According to the doctor, smoking damages the lungs and increases the risk of diseases like lung cancer and heart problems. It also reduces oxygen supply to the body. When I surveyed my area, I found that around 20% people smoke. I collected information from the internet and posters. If someone in the family smokes, we should show them these facts and motivate them to quit smoking for a healthier life.

3. Artificial Respiration - Doctor's Interaction:
(a) A person may need artificial respiration when their breathing stops due to drowning, choking, electric shock, or a severe asthma attack.
(b) Usually, artificial respiration is given temporarily until normal breathing returns. In some serious cases, like coma, it may be needed for a longer time.
(c) Oxygen for artificial respiration is supplied using oxygen cylinders, oxygen concentrators, or hospital pipelines.

4. Measuring Breathing Rate – A Mini Investigation:

(a) Breathing rate in children vs adults:
I measured the breathing rate of my younger brother (child) and my father (adult). I found that children breathe faster than adults. This is because children have smaller lungs and their bodies need more oxygen for growth.

(b) Breathing rate in males vs females:
After checking, I noticed that breathing rates may slightly differ. In general, females have a slightly faster breathing rate than males. This difference may be due to body size, lung capacity, and physical activity.

Why should students use NCERT Solutions for Class 7 Science Chapter 6?

NCERT Solutions for Class 7 Science Chapter 6 – Respiration in Organisms are designed to help students understand how living beings breathe and produce energy. 

Benefits of Using NCERT Solutions for Chapter 6 – Respiration in Organisms:

1. Better Understanding of the Chapter: Explains concepts like cellular respiration, breathing process, and gas exchange in a simple and clear way. Stduents will easily  understand how organisms get energy from food.
2. Helpful for Exam Preparation: Covers all NCERT textbook questions with accurate answers. Gives students confidence for school tests, unit tests, and final exams.
3. Boosts Concept Clarity: Helps students learn the difference between inhalation and exhalation, and aerobic vs. anaerobic respiration. Includes diagrams and examples related to human lungs, gills in fish, and spiracles in insects.
4. Supports Practical Learning: Many activities and experiments from the chapter are explained step-by-step. Encourages observation-based learning (e.g., breathing rate after running, observing fish gills).
5. Supports Learning with Real-Life Connections: Helps relate science to daily life – like why we sneeze, why fish can’t survive out of water, or why we breathe faster after exercise.
6. Accessible Anytime in PDF Format: Available in easy-to-download PDF format for offline study. Saves time and provides a go-to resource for quick help.