Biology · Ecosystems · NEET
NCERT says: dead plant remains such as leaves, bark and flowers, plus dead remains of animals including fecal matter, together make up detritus. It is called the raw material for decomposition because decomposers break it down. Learn this one line, as NEET often quotes it word-for-word.
Detritus is DEAD organic matter. This is a very common NEET trap. The detritus food chain (DFC) begins with dead organic matter, NOT living organisms. If a statement says the detritus food chain starts with living organisms, it is wrong (asked in NEET 2023).
Yes. NCERT clearly includes fecal matter (animal waste/dung) as part of detritus, along with dead leaves, bark, flowers and dead animal bodies. Many students forget the fecal matter part, and NEET checks exactly this in match-the-column questions.
Detritus is fresh dead organic matter (leaves, bark, dead bodies, dung) that goes INTO decomposition. Humus is the dark, amorphous, colloidal substance formed LATE in decomposition (by humification) that resists further breakdown. So detritus is the start, humus is a slow-decomposing product.
Litter usually means the surface layer of fallen dead leaves and plant parts on top of the soil. Detritus is the broader term for ALL dead organic matter, including dead animals and fecal matter, not just fallen leaves. NCERT lists 'litter and detritus' as a distinguish-between pair, so know both.
No. Detritus is the material (the dead stuff). Decomposition is the process of breaking that material into simpler inorganic substances. Detritus is the raw material; decomposition acts ON it. Confusing the two loses easy marks.
Match List I with List II: A. Decomposition B. Detritus C. Mineralisation D. Humification I. Accumulation of dark coloured amorphous colloidal substance II. Release of inorganic nutrients by the activity of microbes in soil III. Breaking down of complex organic matter into inorganic substances IV. Dead remains of plants and animals including fecal matter
Detritivores breakdown detritus into smaller particles. This process is called:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Dead fallen leaves, dead animal bodies, and fecal matter (dung) are classic examples. NCERT also lists bark and flowers. Any dead plant or animal material counts.
Detritus is the raw material for decomposition. Decomposers feed on it and release nutrients back into the soil. It also starts the detritus food chain, which carries most of the energy flow in terrestrial ecosystems.
Detritivores are animals like earthworms that eat detritus and break it into smaller particles (fragmentation). They are different from microbial decomposers (fungi, bacteria) that chemically break detritus down.
The detritus food chain (DFC) begins with dead organic matter (detritus) and is run by decomposers, mainly fungi and bacteria. In terrestrial ecosystems, more energy flows through the DFC than the grazing food chain.
