Science (086) — AI-generated practice question

Decomposers: Decomposers (bacteria, fungi) break down dead organic matter and return nutrients like nitrogen, phosphorus, and minerals to the soil. Without them, these nutrients would remain locked in dead matter. Green plants would be unable to obtain essential minerals needed for growth and protein synthesis, reducing photosynthesis and productivity. This would reduce food availability for all consumers, eventually collapsing the entire ecosystem.

Ozone Layer Depletion: The ozone layer shields Earth from harmful UV radiation. Its depletion allows excess UV rays to reach the surface, damaging chlorophyll and plant tissues, reducing photosynthesis in producers. Since all consumers depend on producers for energy, reduced plant productivity threatens all life in the ecosystem.

Source: Chapter 13, Section 13.2.1; Chapter 5, Section 5.2.1

---

• Examiners expect two clearly separated parts — one for decomposers, one for ozone depletion.
• For decomposers, the key mechanism is nutrient recycling → minerals back to soil → absorbed by plants. Without this, plant growth fails.
• For ozone, the key mechanism is UV radiation damages plants/chlorophyll → less photosynthesis → less food for all trophic levels.
• Always link back to producers first, then the broader ecosystem impact — this shows understanding of interdependence.
• Do not write about CFCs as the answer here; focus on the effect of depletion, not its cause.