An organism that breaks down wastes and dead organisms.

• A. Detritovore
• B. Decomposer
• C. Autotroph
• D. Heterotroph

Answer: (B)

Decomposition and nutrient recycling in ecosystems are driven by decomposers, organisms that break down dead matter and waste by releasing enzymes that digest it into simpler inorganic nutrients. This external digestion lets them absorb the resulting nutrients, returning essential elements like nitrogen and phosphorus to the soil for plants to use. Fungi and many bacteria are classic examples of decomposers.

Detritivores, in contrast, physically ingest detritus and then digest it internally, which is a related process but handled differently than the enzymatic breakdown characteristic of decomposers. Autotrophs are producers that build organic matter from inorganic sources (like photosynthesis), not primarily breaking down dead material. Heterotrophs are consumers that obtain energy by consuming organic matter, but they aren’t defined by breaking down waste or dead organisms through enzymatic decomposition.