Class 10 Science Chapter 13: Our Environment – NCERT Solutions Notes Our Environment is an important Biology chapter in Class 10 Science. It explains ecosystems, food chains, energy flow, and environmental problems like pollution and ozone depletion. It is a theory-based chapter and very scoring in exams. These notes are designed for clear understanding and NCERT-based revision. Key Concepts Environment The environment includes all living (biotic) and non-living (abiotic) components around us. Ecosystem An ecosystem is a system where living organisms interact with each other and with their physical environment. Examples: Forest, pond, grassland Components of Ecosystem Biotic components: Producers (plants) Consumers (animals) Decomposers (bacteria, fungi) Abiotic components: Sunlight Water Air Soil Food Chain A food chain shows the flow of energy from one organism to another. Example: Grass → Deer → Tiger Food Web A network of interconnected food chains. Trophic Levels Each step in a food chain is called a trophic level. Producers → 1st level Primary consumers → 2nd level Secondary consumers → 3rd level Energy Flow Energy flows in one direction and decreases at each trophic level. Only about 10% energy is transferred to the next level (10% law). Biological Magnification Increase in harmful chemicals in food chain at higher trophic levels. Ozone Layer Protects Earth from harmful UV rays. Ozone Depletion Caused by CFCs (chlorofluorocarbons). Effects: Skin cancer Climate imbalance Waste Management Types of Waste: Biodegradable (food waste) Non-biodegradable (plastic) NCERT Important Questions (Concept Based) What is an ecosystem? A system of interaction between living and non-living components. What is food chain? Transfer of energy from one organism to another. What is biological magnification? Increase in toxic substances in food chain. Important Diagrams to Revise Food chain Food web Trophic levels pyramid Why this chapter is important This chapter is frequently asked in exams in: Food chain diagrams Definitions Environmental issues NCERT reasoning questions Final Revision Tip Focus on: 10% energy transfer law Food chain vs food web Ozone layer and CFCs Biodegradable vs non-biodegradable