Q.Distinguish between a grazing food chain and a detritus food chain, giving one example of each.

Step 1. A grazing food chain (GFC) begins with living green plants (producers) at its base and proceeds through herbivores that feed directly on that living plant material, then through one or more levels of carnivores -- for example, grass eaten by a grasshopper, which is eaten by a frog. Step 2. A detritus food chain (DFC) begins instead with dead organic matter, or detritus, and proceeds through detritivores and decomposers that break this dead material down, and through any organisms that in turn feed on those detritivores -- for example, fallen leaf litter broken down by earthworms, which are themselves eaten by a ground-feeding bird. Step 3. The essential distinguishing feature is simply what the chain STARTS with: a living producer for the grazing chain, versus already-dead organic matter for the detritus chain; the grazing chain is usually the dominant energy pathway in most ecosystems, though the detritus chain can dominate in densely vegetated habitats such as wetlands.

Starting-point distinction with an original worked example each

• Assuming detritus food chains are always minor or unimportant, when they can dominate certain ecosystems such as wetlands.
• Giving an example that mixes living and dead starting material within the same chain.