(a) Distinguish between biodegradable and non-biodegradable substances with two examples each.
(b) How do non-biodegradable substances cause environmental problems? Discuss two specific ways.
(c) Even if all waste were biodegradable, could it still harm the environment? Explain your reasoning.
(d) Suggest two practical steps that local municipal bodies can take to manage biodegradable and non-biodegradable wastes effectively.
Generated by claude-sonnet-4-6 · 2026-06-26 01:00 · grounding rag
Model Answer
(a) Biodegradable substances are broken down by biological processes (bacteria, saprophytes). Non-biodegradable substances are not broken down this way and persist in the environment.
- Biodegradable examples: Vegetable peels, spoilt food
- Non-biodegradable examples: Plastic bags, empty medicine strips
(b) Two environmental problems caused by non-biodegradable substances:
- They persist in the environment for a very long time, polluting soil and water bodies.
- They may cause biological magnification — harmful chemicals accumulate and increase in concentration at higher trophic levels, damaging organisms including humans.
(c) Yes, even biodegradable waste can harm the environment. If generated in large quantities, it produces foul smell and harmful gases during decomposition, may contaminate water bodies, and can disturb the balance of nutrients in the soil.
(d) Two practical steps for municipal bodies:
- Collect biodegradable and non-biodegradable wastes separately using different bins and treat them by composting and recycling respectively.
- Ensure proper sewage treatment so that untreated waste does not pollute local water bodies and soil.
Source: Chapter 13, Section 13.2.2 — Managing the Garbage we Produce
---
Explanation
- (a) The distinction must use the key phrase "broken down by biological processes." The textbook explicitly defines both terms this way — use these definitions, not vague ones.
- (b) Biological magnification is the textbook's own example of a specific problem; include it for full marks. Persistence in the environment is the other core point.
- (c) This tests critical thinking beyond definitions. The textbook asks this exact question (Exercise Q8) and the answer is that large quantities of even biodegradable waste cause pollution — gas production, water contamination, etc.
- (d) Activity 13.7 in the textbook explicitly asks students to check whether local bodies treat biodegradable and non-biodegradable wastes separately — make that your anchor point for a strong answer.