Question

The detritus food chain involves decomposers, organisms that feed on dead and decaying material (detritus) while the grazing food chain ________.

• A. begins with autotrophic organisms
• B. fixes inorganic nutrients to soil
• C. begins with carnivores and ends with decomposers
• D. begins with decomposers and ends with carnivores

Answer 1

The correct option is A begins with autotrophic organisms

A food chain refers to the sequence of organisms where one living organism eats another, and later that organism is consumed by larger organisms.

Different organisms occupy different levels in the food chain and each level is referred to as trophic levels.

There are two types of food chain as follows :

• Detritus food chain (DFC) : It begins with detritus (dead and decaying organic material). It is acted upon or consumed by bacteria and fungi. These organisms are microscopic or very small in size. The decomposers release the inorganic nutrients into the surrounding environment from the complex organic matter. Hence option b is incorrect.
• Grazing food chain (GFC) : It begins with autotrophs like green plants, cyanobacteria, etc., that are able to synthesise their own food using sunlight energy and pass on the energy to herbivores (caterpillar) and further to carnivores (thrush). These organisms are macroscopic. The chain begins with producers and ends with consumers like carnivores. Hence option a is correct and option c and d are incorrect.

Figure : Types of food chain