Class 7 Science Chapter 6 Respiration in Organisms Questions with Answers FREE PDF Download
FAQs on NCERT Solutions for Class 7 Science Chapter 6 Respiration In Organisms
1. What are the main steps involved in the process of respiration in organisms as per NCERT Solutions for Class 7 Science Chapter 6?
The main steps of respiration in organisms include:
- Inhalation – Taking in oxygen-rich air into the lungs.
- Exchange of gases – Oxygen from the air is absorbed into the blood and carbon dioxide is released from the blood into the lungs.
- Exhalation – Expelling carbon dioxide-rich air out of the body.
- Cellular respiration – Cells use oxygen to break down glucose and produce energy, releasing carbon dioxide and water as by-products.
2. How does aerobic respiration differ from anaerobic respiration according to NCERT Class 7 Science Chapter 6?
Aerobic respiration occurs in the presence of oxygen and breaks down glucose completely to release more energy, water, and carbon dioxide. In contrast, anaerobic respiration takes place without oxygen, breaks down glucose partially, and produces less energy along with by-products like lactic acid (in muscles) or alcohol (in yeast).
3. Why do athletes breathe faster and deeper after vigorous physical activity, as explained in NCERT Solutions for Class 7 Science Chapter 6?
After vigorous exercise, athletes breathe faster and deeper because their body’s demand for energy increases, leading to rapid production of ATP. More oxygen is needed to release additional energy and remove excess carbon dioxide produced by muscle activity.
4. What are the main components of the human respiratory system mentioned in NCERT Solutions for Class 7 Science Chapter 6?
The human respiratory system is made up of the following major parts:
- Nasal cavity
- Trachea (windpipe)
- Bronchi
- Lungs
- Diaphragm
5. How do plants respire, as described in Class 7 Science Chapter 6 NCERT Solutions?
Plants respire through tiny pores called stomata, mainly on the leaves. They take in oxygen from the air and release carbon dioxide throughout the day and night. During the day, both respiration and photosynthesis occur, but at night only respiration takes place.
6. What is the significance of the exchange of gases in respiration as per NCERT Solutions for Class 7 Science Chapter 6?
The exchange of gases is vital because it supplies oxygen needed for energy production to the body’s cells and removes carbon dioxide, a waste product that must be exhaled to maintain internal balance and prevent toxicity.
7. What causes muscle cramps during heavy exercise, according to the solutions for Class 7 Science Chapter 6?
Muscle cramps during heavy exercise occur due to the accumulation of lactic acid produced during anaerobic respiration, as the muscles temporarily lack sufficient oxygen to meet energy demands.
8. How is breathing in aquatic animals like fish different from breathing in humans, as per NCERT Solutions?
Fish and other aquatic animals use gills to extract dissolved oxygen from water, whereas humans use lungs to absorb oxygen from the air. Fishes lack lungs and their gills allow efficient gas exchange even in water.
9. Why do mountaineers carry oxygen cylinders, explained as per NCERT Solutions for Class 7 Science Chapter 6?
Mountaineers carry oxygen cylinders because the availability of oxygen in the air decreases at higher altitudes. This helps them breathe efficiently and avoid altitude sickness caused by low oxygen levels.
10. What happens to the size of the chest cavity during inhalation and exhalation, as per Class 7 Respiratory System explanation?
During inhalation, the chest cavity expands because the diaphragm contracts and moves downward and the ribs move outward, allowing air to enter the lungs. During exhalation, the chest cavity shrinks as the diaphragm relaxes and moves upward and the ribs move inward, pushing air out of the lungs.
11. How do NCERT Solutions for Class 7 Science Chapter 6 help students prepare for exams?
The solutions provide step-by-step explanations for each question, reinforce key concepts of respiration, and include CBSE pattern answers for thorough preparation, revision, and practice as per the current syllabus.
12. What is the normal breathing rate of an adult at rest as per Class 7 Science Chapter 6?
The normal range of breathing rate for an adult at rest is 15–18 breaths per minute, as stated in NCERT guidelines.
13. Why do we often sneeze when exposed to dust-laden air, according to Class 7 NCERT Solutions?
Sneezing occurs because irritants like dust and pollen enter the nasal cavity and trigger a defense mechanism that expels these particles to protect the respiratory tract.
14. What are some misconceptions about respiration in plants addressed in NCERT Solutions for Class 7 Science Chapter 6?
A common misconception is that plants only respire at night and photosynthesize during the day. In reality, plants respire both day and night, but photosynthesis takes place only in the presence of sunlight.
15. How does the process of gas exchange in the alveoli support efficient respiration, as explained in NCERT Class 7 Science Chapter 6?
The alveoli are tiny air sacs in the lungs where oxygen from inhaled air diffuses into the blood and carbon dioxide diffuses from the blood into the alveoli to be exhaled, maximizing gas exchange surface area and supporting efficient respiration.











