Grazing food chain

(i) The chain begins with producers as the first trophic level.

(ii) Energy for the food chain comes from sun.

(iii) Food chain adds energy into the ecosystem.

(iv) The food chain binds up inorganic nutrients.

Detritus food chain

(i) The chain begins with detritivores and decomposers as the first trophic level.

(ii) Energy for the food chain comes from organic remains of detritus.

(iii) It retrieves food energy from detritus and prevents its wastage.

(iv) The food chain helps in releasing inorganic nutrients to the cycling pool.