What is the role of decomposers in an ecosystem?

• A. They produce nutrient-rich soil through photosynthesis
• B. They decompose living organisms for energy
• C. They transport nutrients through the bloodstream
• D. They break down dead matter and recycle nutrients

Answer: (D)

Decomposers are the recyclers in an ecosystem. They break down dead plants and animals and waste, turning complex organic matter into simpler inorganic nutrients that return to soil and water for reuse by plants. This nutrient recycling keeps the ecosystem productive even after organisms die. The energy in the decomposed material is released as heat, not reused as food for others. So the idea that decomposers break down dead matter and recycle nutrients best describes their role. Photosynthesis is done by producers, not decomposers; transporting nutrients through a bloodstream isn’t a function of decomposers; and while some organisms may act on living tissue, the key concept here is breaking down dead matter to recycle nutrients.