Class 7 Science Chapter 6 Respiration in Organisms Notes FREE PDF Download
Respiration in Organisms Class 7 PDF Notes explores the essential process of respiration, which is crucial for the survival of all living organisms. Students will learn how different organisms, including humans, plants, and animals, obtain and use oxygen to release energy from food. Various types of respiration, such as aerobic and anaerobic respiration, and understanding their significance in sustaining life is covered. This chapter will help you grasp the fundamental role of respiration in maintaining the health and energy of living beings. Visit the CBSE Class 7 Science Revision Notes and CBSE Class 7 Science Syllabus pages for more resources.
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FAQs on Respiration in Organisms Class 7 Notes: CBSE Science Chapter 6
1. What are the key concepts to summarise from Class 7 Science Chapter 6 for a quick revision?
For a quick revision of Respiration in Organisms, focus on these key concepts:
- The definition of cellular respiration and why all organisms need it to get energy from food.
- The two main types of respiration: aerobic (with oxygen) and anaerobic (without oxygen).
- The human respiratory system, including the functions of the nostrils, windpipe, lungs, and diaphragm.
- The mechanism of breathing: inhalation and exhalation.
- Different methods of respiration in other organisms, such as gills in fish, spiracles in insects, and moist skin in earthworms.
- How respiration occurs in plants through stomata in leaves and root cells.
2. How can I briefly explain the difference between aerobic and anaerobic respiration for my notes?
For your revision notes, summarise the difference like this: Aerobic respiration is the process of breaking down glucose to release energy in the presence of oxygen. Its end products are carbon dioxide, water, and a large amount of energy. In contrast, anaerobic respiration is the breakdown of glucose without using oxygen. It produces less energy and results in different end products, such as alcohol and carbon dioxide (in yeast) or lactic acid (in human muscle cells).
3. Why is respiration considered a different process from breathing, and how should I connect these concepts in my revision?
It's a common point of confusion. For your revision, remember this connection: Breathing is the physical process of taking in oxygen (inhalation) and releasing carbon dioxide (exhalation). It is just one part of respiration. Respiration is the complete chemical process that uses the oxygen obtained from breathing to break down food (glucose) inside the body's cells to release energy. In summary, breathing gets the oxygen into the body, while cellular respiration uses that oxygen to produce energy.
4. What are the essential points to remember about the human breathing mechanism?
When revising the human breathing mechanism, focus on the roles of the rib cage and diaphragm. During inhalation, the ribs move up and outwards while the diaphragm moves down. This increases the space in the chest cavity, allowing air to rush into the lungs. During exhalation, the ribs move down and inwards while the diaphragm moves back to its original position. This decreases the space in the chest cavity, pushing air out of the lungs.
5. When revising, what is the best way to compare the respiratory organs of a fish, an earthworm, and an insect?
To effectively compare them in your notes, create a simple table or summary focusing on these key differences:
- Fish: Breathe through special organs called gills, which are designed to extract dissolved oxygen directly from water.
- Earthworm: Breathes through its moist skin. Gas exchange happens directly across the skin's surface, which is supplied with many blood vessels.
- Insect (e.g., Cockroach): Breathes through a network of air tubes called tracheae. Air enters this system through small openings on the side of the body called spiracles.
This highlights how each organism is adapted to respire in its specific environment.
6. How do plants respire, and what key terms should be included in my revision notes?
Plants respire to get energy, just like animals. For your notes, include these key terms: Plants exchange gases mainly through tiny pores on their leaves called stomata. Oxygen enters through the stomata and is used by the cells to break down glucose. Carbon dioxide is then released. It's also important to note that plant roots need oxygen too, which they absorb from air spaces in the soil.
7. Why do our muscle cells sometimes perform anaerobic respiration?
This is an important concept to understand. During heavy physical activity like running, the demand for energy is very high. Sometimes, the oxygen supplied by breathing is not enough to meet this demand. To get extra energy, our muscle cells switch to anaerobic respiration for a short time. This process breaks down glucose without oxygen, producing lactic acid and a small amount of energy. The build-up of lactic acid is what can cause muscle cramps.
8. What is the most effective way to structure short notes for the entire Respiration in Organisms chapter?
To create effective short notes for this chapter, structure them in a logical flow. Start with the core definition of respiration. Next, create two main branches for aerobic and anaerobic respiration, noting their key differences. Then, create sections for 'Respiration in Humans', 'Respiration in Animals' (with sub-points for fish, insects, etc.), and 'Respiration in Plants'. Use bullet points and simple diagrams, like a flowchart for the human breathing mechanism, to make the concepts easy to recap.
