[long_answer] (a) Define 'ecosystem'. Distinguish between biotic and abiotic components, giving two examples of each.
(b) Explain the roles of producers, consumers and decomposers in maintaining the balance of an ecosystem.
(c) Why are green plants called the primary source of energy in any ecosystem? What would happen if all producers were removed from an ecosystem?
Generated by claude-sonnet-4-6 · 2026-06-26 01:00 · grounding rag
Model Answer
(a) An ecosystem is a system in which all living organisms in an area interact with each other and with the non-living constituents of the environment, maintaining a balance in nature.
| | Biotic Components | Abiotic Components |
|---|---|---|
| Definition | Living organisms | Physical/non-living factors |
| Examples | Plants, animals | Temperature, soil |
(b)
- Producers (green plants) synthesise food from inorganic substances using sunlight, making solar energy available to all other organisms.
- Consumers (herbivores, carnivores) depend on producers directly or indirectly for sustenance, transferring energy through trophic levels.
- Decomposers (bacteria, fungi) break down dead remains into simple inorganic substances, returning nutrients to the soil for reuse by plants.
(c) Green plants capture solar energy and convert it into chemical energy (food) through photosynthesis, making them the primary (first) source of energy for all other organisms.
If all producers were removed, consumers would have no food source and would die. Decomposers would also eventually perish. The entire ecosystem would collapse as energy flow would stop completely.
Source: Chapter 13, Section 13.1 & 13.1.1
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Explanation
- (a): Give the textbook definition and clearly separate biotic/abiotic with two examples each — a small table saves words.
- (b): Each role needs one clear sentence; examiners award one mark per component, so don't merge them.
- (c): Two distinct points — why green plants are the primary energy source (photosynthesis/solar energy capture), and consequence of removing producers (collapse of food chain). Both are needed for full marks.
- Keep language concise; CBSE rewards accuracy and coverage over length.