What is the role of decomposers in nutrient cycling and ecosystem health?

• A. Decomposers break down dead organisms, returning nutrients to soil and water, enabling plants to reuse nutrients and supporting food webs.
• B. Decomposers help predators find prey.
• C. Decomposers fix atmospheric nitrogen.
• D. Decomposers are primary producers.

Answer: (B)

Decomposers recycle nutrients. They break down dead organisms and waste, turning complex organic material into simpler inorganic forms like nutrients and minerals that plants can absorb from soil and water. As they decompose, they release nutrients back into the ecosystem, helping plants grow and supporting the broader food web. They also contribute to the carbon cycle by respiring and releasing CO2, and they help build soil organic matter, which improves soil health and fertility for a long time.

This role is what keeps nutrient cycles moving. Without decomposers, nutrients would stay locked in dead matter, plants would struggle to get what they need, and ecosystems could degrade over time.

Other options don’t fit this role. Decomposers don’t actively help predators find prey, they don’t fix atmospheric nitrogen (that’s done by specialized bacteria and cyanobacteria), and they aren’t primary producers (they don’t create energy through photosynthesis).