The Organism -

Energy enters the system via the sun (plants), moves through consumers (animals), and is recycled by decomposers (fungi).

Organisms with complex cells containing a nucleus. This includes: Protists: Mostly single-celled (amoebas). Fungi: Decomposers (mushrooms, molds). The Organism

Single-celled, often found in extreme environments like hot springs or salt lakes. Energy enters the system via the sun (plants),