CBSE · Class 10 · Science · Chapter 13
Our Environment — Class 10 Science (CBSE) explained
- Board exam 2026-27
- 4 lessons
- 28 scenes
- About 22 min
- Updated
Quick answer
Our Environment is Chapter 13 of CBSE Class 10 Science. It covers ecosystem components, producers make food, food webs, chemical entry pathways, ozone and protection and waste categories. AI Lessons teaches it in 4 narrated lessons (about 22 minutes) with an AI tutor and board-pattern practice.
What you’ll learn
Lesson 1: Ecosystems and Their Components
5 min- An Ecosystem Is an Interacting System
- Recognise Ecosystems Around Us
- Think Through an Aquarium
- Producers Make Food
- Consumers Depend on Produced Food
- Decomposers Return Substances to the Soil
- Food Chains Have Trophic Levels
Lesson 2: Food Webs, Energy Flow and Biological Magnification
5 min- Sunlight Enters as Food Energy
- Only an Average of 10% Reaches the Next Level
- Energy Loss Limits Food-Chain Length
- Many Food Chains Form a Food Web
- Energy Flow Is Unidirectional
- How Chemicals Enter Food Chains
- Biological Magnification
Lesson 3: Ozone and the Breakdown of Waste
6 min- Ozone's Role Depends on Where It Is
- Ultraviolet Radiation Helps Form Ozone
- Ozone Depletion and the CFC Agreement
- Investigating Ozone Protection
- Observe What Happens to Household Waste
- Why Biological Processes Do Not Break Down Everything
- Biodegradable and Non-Biodegradable Substances
Lesson 4: Waste Management and Chapter Practice
6 min- Investigate Waste at Home and School
- Investigate Sewage and Industrial Waste
- Lifestyle and Packaging Change Waste
- Disposable Cups: Consider the Trade-offsNot assessed
- Research Electronic Waste and Plastic Recycling
- Practise Classification and Explanation
- Recap: Connect the Chapter and Begin Practice
Key concepts
- Ecosystem components
- The living organisms are its biotic components. Its abiotic components include physical factors like temperature, rainfall, wind, soil and minerals.
- Producers make food
- All green plants and certain bacteria produce food in this way and are called producers.
- Food webs
- A straight food chain shows one series of feeding relationships.
- Chemical entry pathways
- Pesticides and other chemicals are used to protect crops from diseases and pests.
- Ozone and protection
- An ozone molecule is formed by three atoms of oxygen. The oxygen we normally refer to is essential for all aerobic forms of life.
- Waste categories
- Substances broken down by biological processes are biodegradable. Substances not broken down in this manner are non-biodegradable.
- Changing waste patterns
- Changes in how we live and use materials affect the waste we generate.
- Electronic waste and recycling research
- In Activity thirteen point nine, investigate electronic-item disposal and plastic recycling.
Exam focus
- Board exam
- CBSE assesses this chapter in the 2026-27 year-end board examination.
- Syllabus
- Our environment: Eco-system, Environmental problems, Ozone depletion, waste production and their solutions. Biodegradable and non-biodegradable substances.
- Not assessed
- These parts go beyond the 2026-27 syllabus and are taught for understanding only: Disposable Cups: Consider the Trade-offs.
- Paper pattern
- 80 marks, 3 hours, 39 questions in three sections (A Biology, B Chemistry, C Physics); internal assessment 20. Units: I Chemical Substances 25, II World of Living 25, III Natural Phenomena 12, IV Effects of Current 13, V Natural Resources 5.
- Question style
- About 50% of board questions are competency-focused: case-based, source-based, integrated, data interpretation, situational and application-oriented.
- Practice in the app
- 90 board-pattern questions with marking schemes: 27 multiple choice (1 mark), 14 assertion–reason (1 mark), 20 very short answer (2 marks), 17 short answer (3 marks), 4 long answer (5 marks) and 8 case-based (4 marks).
Sample questions with marking points
Board-pattern questions from the AI Lessons practice set for this chapter. The marking points show what an examiner looks for; full model answers are in the app.
Very short answer2 marks
In a garden, decomposer microorganisms are lost. State two consequences for the ecosystem.
Marking points
- States that dead remains and waste products would accumulate.1
- States that replenishment of soil with simple inorganic substances for reuse by plants would be disrupted.1
Short answer3 marks
A non-degradable pesticide is washed into a water body. Explain how humans occupying the top level of a contaminated food chain can accumulate the highest concentration of this pesticide.
Marking points
- Aquatic plants and animals take up the pesticide from water, introducing it into food chains.1
- The non-degradable pesticide accumulates progressively at successive trophic levels.1
- Humans at the top level accumulate the maximum concentration; the phenomenon is biological magnification.1
Long answer5 marks
A student describes a garden as merely a collection of plants and animals. Explain why this description is incomplete. Identify its biotic and abiotic components, explain the roles of producers and consumers, and trace how decomposers make substances available to plants again.
Marking points
- Identifies living organisms as biotic components and recognises their interactions.0.5
- Identifies suitable abiotic components as part of the same ecosystem.0.5
- Explains that producers make organic food from inorganic substances using sunlight in the presence of chlorophyll.1
- Explains that consumers obtain produced food directly from producers or indirectly through other consumers.1
- Explains that bacteria and fungi break down complex organic substances in dead remains and waste into simple inorganic substances.1
- States that these inorganic substances enter the soil and are reused by plants.1
Frequently asked questions
What does Our Environment cover in Class 10 Science?
It covers ecosystem components, producers make food, food webs, chemical entry pathways, ozone and protection and waste categories. AI Lessons teaches it in 4 lessons: Ecosystems and Their Components, Food Webs, Energy Flow and Biological Magnification, Ozone and the Breakdown of Waste and Waste Management and Chapter Practice.
Is Our Environment in the CBSE Class 10 board exam?
Yes. CBSE assesses Our Environment in the 2026-27 year-end board examination. 1 short part goes beyond the syllabus and is marked as not assessed.
Which group consists entirely of abiotic components of an ecosystem?
Temperature, rainfall and minerals. Temperature, rainfall and minerals are non-living components.
What are producers?
All green plants and certain bacteria produce food in this way and are called producers.
Which criterion determines whether a discarded substance is biodegradable?
Whether biological processes break it down. Biodegradability is determined by breakdown through biological processes.
What kinds of questions come from Our Environment?
Board-pattern questions for this chapter include multiple choice (1 mark), assertion–reason (1 mark), very short answer (2 marks), short answer (3 marks), long answer (5 marks) and case-based (4 marks). AI Lessons has 90 of them for Our Environment, each with a marking scheme.
How does AI Lessons teach Our Environment?
As 4 narrated, animated lessons (28 scenes, about 22 minutes in all), with an AI tutor that knows the step you are on and board-pattern practice with marking schemes. The full lessons open after sign-in on an AI Lessons account.
Watch the full lesson
Our Environment, as a narrated, animated lesson
4 lessons · 28 animated scenes · about 22 minutes, with an AI tutor that knows the step you are on and 90 board-pattern questions with marking schemes.
Lessons open after sign-in. A parent or guardian holds the account and adds each child.