Question

what do you mean by detritus food chain and grazing food chain?

Answer 1

In detritus food chain, the first trophic level is the dead and decaying organic matter.

Primary consumers form the next trophic level,they are 'detritivores' including protozoans, bacteria, fungi, etc which feed upon the detritus.

Detritus→ Bacteria/ Fungi (Detrivores) → plants (consume nutrients release by detrivores in soil) → Herbivore → Carnivore

The grazing food chain includes the producers i.e green plants at first trophic level which is further consumed by primary consumers i.e herbivores. These herbivores form the next trophic level.