Science (086) — AI-generated practice question

Role of Decomposers:
Decomposers (bacteria and fungi) break down dead and decaying organic matter — dead plants, animals, and their waste — into simple inorganic substances like minerals and nutrients, which are returned to the soil. This makes nutrients available again for producers (plants), completing the nutrient cycle in the ecosystem.

If Decomposers Were Absent:
Dead organic matter would keep accumulating in the environment. Nutrients locked in dead organisms would never be recycled back into the soil. This would deprive producers of essential minerals, disrupting the entire food chain. The ecosystem would eventually collapse due to nutrient depletion and overwhelming accumulation of waste.

Source: Our Environment, Chapter 13

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• Examiners expect two clear parts: the role (nutrient/mineral recycling) and the consequence of absence (accumulation of dead matter + nutrient depletion).
• The source passage emphasises interdependence of ecosystem components and biodegradable waste — tie decomposers to biodegradable breakdown and nutrient cycling.
• Avoid vague phrases like "they help the environment." Be specific: break down → release minerals → absorbed by producers.
• At 3 marks, aim for ~2–3 focused points per part — do not over-write.