2.2.11—Food chains and trophic levels
- Syllabus
- First assessment 2026
- Objective
- 2.2.11
- Level
- SL
Trophic levels track stages of consumer transfer; decomposers receive dead matter and waste from many levels, so they do not fit one fixed level.
Producers are level 1 and primary consumers level 2; decomposers transform material from several levels and return inorganic nutrients.
A fungus can decompose dead leaves from producers and carcasses from consumers, linking several trophic pathways.
Usually no; show their links to dead material from multiple levels.
Omitting decomposers from a simple chain does not mean they are absent.