Our Environment — Science Class 10 Notes (CBSE & HBSE)
Free NCERT Science notes for Our Environment (Class 10) on Siksha Sarovar, aligned to CBSE and Haryana Board (HBSE). This chapter is broken into 3 topics with clear explanations, formulas, solved examples and board-pattern practice — free to read, no sign-up required.
Board exam focus — Our Environment (CBSE & HBSE)
Covers the interactions between living organisms and their physical surroundings. CBSE emphasizes ecological balance and waste management; HBSE focuses on food chains and ozone layer importance.
Ecosystem and its Components
An ecosystem consists of biotic (living) and abiotic (non-living) components interacting with each other.
1. Biotic Components
- Producers: Organisms that produce food using solar energy (Green plants).
- Consumers: Organisms that depend on producers (Herbivores, Carnivores, Omnivores).
- Decomposers: Organisms that break down dead remains and waste (Fungi, Bacteria). They help in nutrient recycling.
2. Abiotic Components
Physical factors like temperature, rainfall, wind, soil, and minerals.
Food Chains and Food Webs
1. Food Chain
A series of organisms where each one is eaten by the next.
- Example: Grass (Producer) → Deer (Primary Consumer) → Lion (Secondary Consumer).
- Trophic Levels: Each step in a food chain is a trophic level.
2. The 10% Law (Lindeman's Law)
Only 10% of the energy is transferred from one trophic level to the next. The rest is lost as heat to the environment or used for metabolic processes.
3. Biological Magnification
The increase in concentration of harmful chemicals (like pesticides) at each successive trophic level. Humans, being at the top, often accumulate the highest levels.
Impact of Human Activities
Our lifestyle produces waste and affects atmospheric layers.
1. Ozone Layer Depletion
The Ozone (O₃) layer in the upper atmosphere absorbs harmful UV radiation from the sun.
- Cause: Chlorofluorocarbons (CFCs) used in refrigerators and fire extinguishers.
- Effect: Increased skin cancer, cataracts, and damage to crops.
2. Waste Management
- Biodegradable Waste: Substances broken down by biological processes (e.g., fruit peels, paper).
- Non-Biodegradable Waste: Substances not broken down by bacteria (e.g., plastics, glass, metals).
Frequently asked questions
Are these Our Environment notes free?
Yes — the Our Environment notes for Science (Class 10) on Siksha Sarovar are completely free to read, with no account required.
Do these notes follow CBSE and HBSE?
Yes. The Our Environment notes are NCERT-aligned and include guidance for both CBSE and Haryana Board (HBSE), with important questions and MCQs for revision.
What does the Our Environment chapter cover?
Concept explanations, key formulas and definitions, fully solved examples and board-pattern practice questions for Our Environment.