In which ecosystem, a larger fraction of energy flows through detritus food chain (DFC) than through grazing food chain (GFC)?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Terrestrial ecosystem
Option (1) Pond ecosystem — Incorrect. In an aquatic ecosystem the grazing food chain is the major path of energy flow.
Option (4) Terrestrial ecosystem — Correct. On land much of the plant matter dies and falls as litter, so more energy passes through decomposers.
NCERT Extract:
Energy Flow – “In an aquatic ecosystem, GFC is the major conduit for energy flow. As against this, in a terrestrial ecosystem, a much larger fraction of energy flows through the detritus food chain than through the GFC. Detritus food chain may be connected with the grazing food chain at some levels: some of the organisms of DFC are prey to the GFC animals, and in a natural ecosystem, some animals like cockroaches, crows, etc., are omnivores.”