Biology · Ecosystems · NEET
A detritivore is an animal that feeds on detritus (dead plants, dead animals, and fecal matter). The NCERT example is the earthworm. Detritivores physically eat the dead matter and break it into smaller particles. They start decomposition by making the dead material smaller so microbes can act on it faster.
Fragmentation is the breaking down of detritus into smaller particles by detritivores. It is the FIRST step in the process of decomposition. NCERT says exactly: 'Detritivores (e.g., earthworm) break down detritus into smaller particles. This process is called fragmentation.' Smaller pieces mean more surface area for microbes to attack later.
An earthworm is a DETRITIVORE, not a decomposer. Detritivores physically eat and fragment dead matter. Decomposers are microbes (bacteria and fungi) that chemically break detritus into simple substances. NEET has trapped students here - do not call the earthworm a decomposer. The earthworm performs fragmentation, the microbes perform catabolism.
Fragmentation is done by detritivores (like earthworm) and only breaks detritus into smaller PHYSICAL particles. Catabolism is done by bacterial and fungal ENZYMES and chemically degrades detritus into simpler inorganic substances. Fragmentation is mechanical; catabolism is chemical. Earthworm = fragmentation, NOT catabolism (a common NEET trap).
The order is: Fragmentation, Leaching, Catabolism, Humification, and Mineralisation. Fragmentation (by detritivores) comes first. A memory line: 'Fine Leaves Cook Hot Meals' (Fragmentation, Leaching, Catabolism, Humification, Mineralisation).
Detritivores breakdown detritus into smaller particles. This process is called:
Identify the correct statements: A. Detritivores perform fragmentation. B. The humus is further degraded by some microbes during mineralisation. C. Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching. D. The detritus food chain begins with living organisms. E. Earthworms break down detritus into smaller particles by a process called catabolism.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Yes. The steps are fragmentation, leaching, catabolism, humification and mineralisation, in that order. Fragmentation, done by detritivores, is the first step.
The earthworm. NCERT writes: 'Detritivores (e.g., earthworm) break down detritus into smaller particles.'
Breaking detritus into smaller particles increases the surface area. More surface area lets bacterial and fungal enzymes act faster during catabolism, so decomposition speeds up.
No. Fragmentation is only physical breaking into smaller pieces. The chemical change into simple inorganic substances happens later, during catabolism by microbes.
Because students confuse fragmentation (physical, by earthworms) with catabolism (chemical, by microbes), and confuse detritivores with decomposers. NEET repeatedly uses these swaps as traps (2022, 2023).
