CBSE Class 7 Science Revision Notes Chapter 10

CBSE Class 7 Science Revision Notes Chapter 10 – Respiration in Organisms

NCERT Class 7 Science Chapter 10, Respiration in Organisms discusses the topics of respiration, the causes of respiration, cell respiration and its location, and a few other concepts associated with respiration. Students can rely on revision notes to show these processes with the aid of diagrams since it involves key terminology and the working of various organs involved with breathing.

Respiration in Organisms Notes for Class 7 provided by Extramarks help students effectively revise the chapter. After a thorough analysis of the revised CBSE syllabus, subject matter experts have carefully prepared the revision notes. These notes include all of the topics mentioned in the chapter, boosting students’ confidence in their exam preparations. 

The topics that are covered in Class 7 Science Chapter 10 are:

  • Why Do We Respire?
  • Breathing
  • How Do We Breathe?
  • What Do We Breathe Out?
  • Breathing in Other Animals
    • Cockroach
    • Earthworms
  • Breathing Underwater
  • Do Plants Also Respire?

Extramarks’ Revision Notes on Respiration in Organisms will enable students to review the entire chapter in less time without skipping any crucial information. The detailed explanations provided will aid students to remember important points and write quality answers for the exams. 

Revision Notes for CBSE Class 7 Science Chapter 10

Access Class 7 Science Chapter 10 – Respiration in Organisms Notes

Types of Respiration

  1. External Respiration

Breathing, or external respiration, is the process of taking in oxygen from the atmosphere while exhaling carbon dioxide back into the atmosphere.

At the same time, gases are exchanged in and out of the blood.

  1. Internal Respiration

During internal respiration, a variety of chemical processes break down food in body cells.

The two types of internal respiration are as follows:

  • Aerobic respiration
  • Oxygen is required for aerobic respiration to take place.
  • Aerobic respiration produces carbon dioxide and water as its byproducts.
  • Most organisms engage in aerobic respiration.
  • Anaerobic Respiration 
  • Whenever there is no oxygen present, anaerobic respiration takes place.
  • Anaerobic respiration is a process that most microorganisms are able to perform.
  • Alcohol and carbon dioxide are produced at the end of anaerobic respiration.
  • In some instances, anaerobic respiration ends with the production of lactic acid.

Respiration in Plants:

Stomata, the pores used by plants for breathing, allow gaseous exchange through diffusion.

Lenticels are stem-mounted apertures that facilitate gaseous exchange through diffusion.

Oxygen dissolved in soil water can be exchanged gaseously in roots through stomatal pores.

Respiration in Animals:

Animals’ breathing patterns vary according to their characteristics, for example:

  • Earthworms breathe through their skin.
  • Insects breathe through the surface of their entire bodies.
  • Fish breathe through their gills.
  • Frogs breathe through their smooth, moist skin in the water; whereas, on land, they breathe through their lungs.

Respiration in Humans:

Air that is inhaled travels down the windpipe and into the lungs after entering the nasal cavity through the nostrils.

A part of the respiration process, during which an organism inhales carbon dioxide-rich air and exhales oxygen-rich air, is breathing.

Different creatures have various respiratory systems for exchanging gases.

When we breathe in, our lungs expand, and when we exhale, the air leaves our bodies, they contract.

Increasing physical effort quickens the rate of breathing.

Animals like cows, buffaloes, dogs, and cats have respiratory systems and breathing patterns that are similar to those of humans.

CBSE Class 7 Science Respiration in Organisms Notes

The concept of respiration is explained in Class 7 Revision Notes on Respiration in Organisms. During respiration, the glucose is broken down into carbon dioxide and water using the oxygen we breathe in. Energy is released as a result of this process. Students can consult the NCERT Class 7 Science Chapter 10 Notes to learn more about what respiration is and how it works. The process of respiration and its significance have been explained in point form, so students can easily recall these concepts and elaborate on them in the exams.

Depending on the process involved, respiration can be classified into internal and external respiration. Internal respiration can be further divided into anaerobic and aerobic respiration, based on whether oxygen is used during the respiration process. Students can gain a clear understanding of these classifications by using the Class 7 Science Chapter 10 Notes.

The next section in the chapter Respiration in Organisms will discuss the respiration process in a variety of organisms, including plants, animals, and people. Animals of various types and species have different respiratory systems. For example, earthworms breathe through their skin. These notes contain examples like these from Chapter 10 of NCERT Science for Class 7.

The Revision Notes also include pointers on breathing and explain how physical activity affects breathing rate and how breathing differs for various types of organisms. The respiratory system of animals like cows, dogs, cats, and buffaloes is similar to that of humans. These facts and other crucial information is included in the revision notes that may have been overlooked by students while reading the chapter. 

Students must split their time to cover essential and crucial topics of a chapter to perform well in the exam. For quicker and more effective revisions, they can utilise the Class 7 Science Chapter 10 Notes before exams. These comprehensive notes provided by Extramarks will help them save time with accurate and precise content. 

These notes are easily available from the website, where students can consult them any time. They can quickly learn and revise important concepts as the notes are brief and clear.

Students will also be able to provide quality responses in the tests by reading the Class 7 Science Chapter 10 Notes. This is because the notes convey the information in a point-by-point manner. Therefore, they can utilise these notes to improve their answers in the tests with the help of the specific points provided.

FAQs (Frequently Asked Questions)

1. What is respiration?

 Stored food is oxidised in the presence of oxygen during respiration, and carbon dioxide is released from the system to provide energy to the body’s cells and enable them to function. An organism removes carbon dioxide produced during energy-producing processes and provides oxygen to its cells and tissues for metabolism during respiration. This is made possible by mechanisms involving physics and chemistry (such as breathing and diffusion).

2. What is the importance of respiration?

Respiration is essential as it produces the energy needed for the body’s regular operations. Cells receive oxygen through respiration, which also eliminates dangerous carbon dioxide. As part of the energy released by breathing, heat is also produced. Food that has been stored in the body is oxidised in the presence of oxygen and carbon dioxide is expelled from the system to give the body’s cells the energy they require to function. It regulates the body’s cycle of energy transfer and is an important phenomenon.

3. What is breathing?

When an organism breathes, oxygen-rich air is taken in by its body and carbon dioxide-rich air is expelled with the aid of breathing organs. Both inhalation and exhalation take place frequently during breathing. A breath is defined as an inhalation and an exhalation. The first step is inspiration, or inhaling. During the inhalation process, the diaphragm undergoes contraction and pulls downward. The muscles located between the ribs have a tendency to tighten and pull upward simultaneously.

4. Write the differences and similarities between anaerobic and aerobic respiration.


Energy is released during each respiration process.

Both methods of respiration produce carbon dioxide. 



In the presence of oxygen, aerobic respiration occurs, whereas anaerobic respiration occurs in the absence of oxygen.

While glucose is only partially broken down during anaerobic respiration, it is completely broken down during aerobic respiration.

5. Why do human beings often sneeze when they inhale a lot of dust-laden air?

We are surrounded by heavily polluted air. It has a variety of constituent parts, including pollen, dust, smoke, and dirt. These specks travel through the nasal cavity as you breathe. Small hairs cover a lot of the nasal cavity. The nasal cavity hairs in our noses trap the polluted air particles when we breathe them in. The nose becomes unnecessarily irritated as a result of the dirt particles being trapped. This is the reason why when breathing in dusty air, people sneeze.