NCERT Class 10 Science Science: Chapter 5 — Life Processes
This chapter, 'Life Processes,' from NCERT Class 10 Science, delves into the fundamental characteristics that distinguish living organisms from non-living ones. It explains that while visible movement is a common indicator, it's not sufficient. The chapter highlights the necessity of molecular movement for life, even in seemingly inactive organisms. It introduces 'life processes' as the maintenance functions essential for survival, repair, and organisation of living structures. These processes require energy, primarily derived from food through nutrition. The chapter discusses how organisms obtain and utilise energy, mentioning respiration as a key process involving oxygen for breaking down food. It also touches upon the challenges faced by multicellular organisms in transporting nutrients and oxygen to all cells and the need for excretion to remove harmful waste by-products. Understanding these processes is crucial for comprehending biological functions and the continuity of life.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 10 |
| Subject | Science |
| Book | Science |
| Chapter | Chapter 5 — Life Processes |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 5 minutes |
| Word count | 947 |
Learning outcomes
- Differentiate between living and non-living things based on life processes.
- Understand the necessity of molecular movement for life.
- Define and identify key life processes like nutrition, respiration, transport, and excretion.
- Explain the role of energy in maintaining living organisms.
- Recognize the challenges and solutions for nutrient and gas transport in multicellular organisms.
Vocabulary
| Word | Meaning |
|---|---|
| Life Processes | The maintenance functions of living organisms that collectively perform the job of keeping the organism alive. |
| Nutrition | The process of transferring a source of energy from outside the body to the inside, commonly known as food. |
| Respiration | The process of acquiring oxygen from outside the body and using it to break down food sources for cellular needs. |
| Excretion | The process of removing and discarding waste by-products from the body. |
| Multicellular organisms | Organisms made up of more than one cell, often with specialised tissues and organs. |
| Molecular movement | Movement of molecules within an organism, essential for maintaining life. |
The complete chapter text is read in the official NCERT PDF viewer below (streamed from ncert.nic.in). This page provides NCERT Help study material — summary, vocabulary, practice questions, and FAQs — not a full reproduction of the textbook.
Read chapter online
This PDF is loaded from the official NCERT website (ncert.nic.in). Use the page buttons below to read — download is disabled on NCERT Help.
Read page by page below. PDF is streamed from the official NCERT website — no download button on this page.
Practice questions
- What is the primary reason why molecular movement is considered essential for life? Answer: Molecular movement is essential for life because it allows organisms to repair and maintain their organised structures, which are constantly breaking down due to environmental effects.
- Define 'life processes'. Answer: Life processes are the maintenance functions that living organisms perform continuously, even when inactive, to prevent damage and breakdown of their structures.
- What is the role of nutrition in living organisms? Answer: Nutrition provides the energy and raw materials from outside the body that are required for growth and carrying out life processes.
- Explain the basic concept of respiration as described in the chapter. Answer: Respiration is the process of taking in oxygen from the environment and using it to break down food molecules to release energy for cellular needs.
- Why is a transportation system necessary in multicellular organisms? Answer: A transportation system is necessary in multicellular organisms because specialised tissues take up food and oxygen at one place, and these need to be carried to all other parts of the body.
- What is excretion and why is it important? Answer: Excretion is the process of removing waste by-products from the body. It is important because these wastes can be useless or even harmful to the cells.
Frequently asked questions
What are the basic characteristics that help us identify if something is alive?
We often look for movement, growth, breathing, and molecular activity. While visible movement is common, molecular movement is considered a more fundamental indicator of life.
Why is continuous maintenance necessary for living organisms?
Living organisms are organised structures that are prone to breaking down over time due to environmental effects. Maintenance processes are needed to repair and maintain these structures.
Where does the energy for life processes come from?
The energy for life processes comes from outside the organism's body, primarily from food, which is then processed through nutrition.
What is the main function of respiration?
Respiration's main function is to break down food sources using oxygen to generate energy that fuels the molecular movements needed for maintaining life.
How do single-celled organisms differ from multicellular organisms regarding life processes?
In single-celled organisms, the entire surface interacts with the environment for functions like nutrient intake and waste removal. Multicellular organisms have specialised tissues and systems for these tasks due to their increased complexity and size.
What is the purpose of excretion in living beings?
Excretion is the process of removing waste by-products generated during chemical reactions (like energy generation) that are either useless or potentially harmful to the organism.
Related resources
Important topics
Topics covered
NCERT Class 10 Science — Science — Chapter 5 — Life Processes. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.