Question

Which of the following statements is incorrect with respect to DFC ?

• A. Detritivores meet their energy requirements from the sun
• B. It is composed of detritus-eating organisms
• C. In terrestrial ecosystems much larger energy flows through this food chain
• D. They release nutrients in soil for autotrophs

Answer 1

The correct option is A Detritivores meet their energy requirements from the sun

A food chain refers to the chronological series of organisms each depending on others for food. Different organisms occupy different levels in the food chain and each level is called trophic level.

There are two types of food chains as follows :

1. Detritus food chain : It is also known as DFC and begins with dead and decaying organic material. Decomposers like bacteria and fungi (heterotrophic organisms) feed on dead and decaying material and meet their energy requirements by converting the detritus into simple organic compounds and inorganic molecules.

These organisms while degrading the material release nutrients into the soil which can be taken up by plants. Hence option a is incorrect and option b and d are correct.

2. Grazing food chain : It is also knnown as GFC, begins with autotrophs like green plants, cyaobacteria, etc., that are able to synthesise their own food by utilizing sunlight energy and pass on the energy to herbivores and further to carnivores.

In terrestrial ecosystems like forests the amount of detritus formed is huge when compared to other ecosystems because of the large number of trees and animal species in these forests and the amount of excreta they are generating. Therefore, in terrestrial ecosystems, a much larger fraction of energy flows via the detritus food chain. Hence option c is correct.