Q1. [2] straightforward exam-ready
Define 'biodegradable substances'. Give one example each of a biodegradable and a non-biodegradable waste commonly generated at home.
Generated by claude-sonnet-4-6 · 2026-06-26 00:59 · grounding rag
Model Answer
Biodegradable substances: Substances that are broken down by biological processes (action of bacteria or other saprophytes) are called biodegradable substances.
- Biodegradable waste (home example): Vegetable peels / spoilt food / used tea leaves.
- Non-biodegradable waste (home example): Plastic bags / empty medicine strips / bubble packs.
Source: Our Environment, Section 13.2.2
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Explanation
- The definition must include the key idea: broken down by biological processes — not just "broken down naturally." Examiners look for this specific phrase from the textbook.
- One mark is for the definition; one mark is split between the two examples (both must be correct to score).
- Common mistakes: writing "decomposed by nature" (too vague) or giving examples that don't clearly belong to home-generated waste. Stick to kitchen/household items like vegetable peels (biodegradable) and plastic/medicine strips (non-biodegradable).