How do harmful chemicals get accumulated progressively at each trophic level in a food chain ?
Generated by claude-sonnet-4-6 · 2026-06-15 06:44 · grounding rag
Model Answer
Harmful chemicals like pesticides are absorbed by plants from soil and water. Since these chemicals are non-biodegradable, they are not broken down and keep accumulating in the body of organisms. At each successive trophic level, the concentration increases. This is called biological magnification. Humans, being at the top, accumulate the maximum concentration.
Source: Chapter 13, Section 13.1.1 (Food Chains and Webs)
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Explanation
- The key phrase examiners look for is "non-biodegradable" — this explains why chemicals accumulate rather than break down.
- Mention the term biological magnification for full marks.
- State clearly that concentration increases at each trophic level and is maximum in humans (top consumers).
- Don't waste words describing pesticide use in farming — focus on how accumulation happens up the chain.