Question

Assertion: GFC is a major conduit for energy flow in the aquatic ecosystem.
Reason: DFC may be connected with GFC at some levels.
(a) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
(b) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
(c) Assertion is correct but Reason is incorrect
(d) Both Assertion and Reason are incorrect

Answer 1

Hint: GFC or Grazing food chain starts at the producer level and ends on secondary or tertiary consumer and is the chief energy transfer form. DFC or Detritus food chain is the chain that begins with detritivores or decomposers.

Complete answer:
In an aquatic ecosystem, GFC is the main conduit of energy because it is the chief form of energy transfer where the chain begins with the primary producers like phytoplankton, which are eaten by the zooplanktons. The zooplankton are eaten by different fishes which are eaten by bigger fishes or birds like Pelicans or Cranes. Grazing food chains are the ones that have the first trophic level occupied by photosynthetic organisms which later transfer energy to the herbivores.
In an aquatic ecosystem, the detritivores at some point enter the GFC as they are eaten by larger organisms, thus transferring the energy into the GFC. Hence, the DFC is connected to GFC at some levels. Thus, both Assertion and Reason are true, but the statements do not explain each other.
So, the answer is, “ Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.”

Note: In an aquatic ecosystem, decomposition is very less. That is the reason why GFC is the major conduit of energy in an aquatic ecosystem, as opposed to the DFC as the major conduit in a land ecosystem. In the land ecosystem, the detritivores decompose organic substances to add nutrients to the soil which help the plants gain nourishment, thus establishing a DFC.