3
Question Question 3
Give any two ways in which non-biodegradable substances would affect the environment.
Two ways in which non-biodegradable substances would affect the environment are:
- Non-biodegradable substances, such as plastic, contribute to environmental pollution by accumulating in ecosystems, water bodies, and soil disrupting the ecological balance and harming wildlife.
- They can cause bio-magnification if their hazardous chemicals enter the food chain.
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BRIGHT TUTORIALS
CBSE Class X | Academic Year 2026-2027
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Science | Chapter 13: Our EnvironmentWeb Content
Chapter 13: Our Environment — Quick Revision Guide
Introduction
Our environment is a complex web of living and non-living components. This chapter covers ecosystems, food chains, energy flow, ozone layer depletion, and waste management.
Key Points at a Glance
- Ecosystem: biotic (producers, consumers, decomposers) + abiotic (temperature, water, soil, light)
- Food chain: linear energy transfer; Grass → Grasshopper → Frog → Snake → Hawk
- Trophic levels: T1 (producers), T2 (primary consumers), T3, T4; usually 4–5 levels max
- 10% law (Lindeman): only 10% energy transfers to next level; rest lost as heat in life processes
- Food web: interconnected chains; more stable; if one species declines, alternatives exist
- Biological magnification: non-biodegradable chemicals (DDT) concentrate at higher trophic levels
- Ozone (O3) in stratosphere absorbs UV; CFCs deplete ozone; Montreal Protocol (1987) limits CFCs
- Biodegradable waste: broken down by microorganisms; composting, vermicomposting, biogas
- Non-biodegradable waste: persists; plastic, glass, DDT; reduce, reuse, recycle
- Problems: biomagnification, plastic pollution, e-waste toxicity, air pollution from burning waste
Real-World Connections
Banning single-use plastic reduces pollution; composting reduces landfill load; ozone layer is slowly recovering; understanding food chains helps conservation; DDT ban protected bird populations.
Quick Self-Test (5 Questions)
- What is the most important concept you learned from this chapter?
- Can you write three key equations/formulae from this chapter from memory?
- Draw a labelled diagram relevant to this chapter without looking at your notes.
- Explain one real-world application of a concept from this chapter.
- What is one common mistake students make in this chapter, and how can you avoid it?
Further Study
- NCERT Textbook Chapter 13
- NCERT Exemplar Problems
- Bright Tutorials Detailed Notes: ch13-our-environment.html
- Bright Tutorials Practice Questions: ch13-our-environment.html
- Previous Year CBSE Board Papers