Q1. [3]
Differentiate between food chain and food web. In a food chain consisting of deer, grass and tiger, if the population of deer decreases, what will happen to the population of organisms belonging to the first and third trophic levels ?
Previously asked in CBSE board exam
2024 31/5/1 Q33
Generated by claude-sonnet-4-6 · 2026-06-15 06:43 · grounding rag
Model Answer
Food Chain vs Food Web:
| Food Chain | Food Web |
|---|---|
| A single linear sequence of organisms where each feeds on the one before it. | A network of interconnected food chains in an ecosystem. |
| Simple and less stable. | Complex and more stable. |
Effect of decrease in deer population:
The food chain is: Grass → Deer → Tiger
- First trophic level (Grass): Population of grass will increase, as fewer deer are present to consume it.
- Third trophic level (Tiger): Population of tiger will decrease, as their primary food source (deer) has reduced.
Source: Our Environment, Section 13.1.1
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Explanation
- Examiners expect a clear distinction between food chain and food web — one mark for differentiation.
- For the second part, correctly identify grass as 1st trophic level and tiger as 3rd trophic level — this is a common error students make.
- State the effect on both trophic levels with brief reasoning (1 mark each).
- A simple table for differentiation saves time and looks neat in board exams.
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