Ans: The starting point in a grazing food chain are the producers. In the grazing food chain, energy is acquired from the sun.

A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another. In a food chain, each organism occupies a different trophic level, defined by how many energy transfers separate it from the basic input of the chain.

Mangroves – shed leaves – detritus – shrimps – small fish.

A grazing food chain is the one where the main source of energy is the producers or green plants whereas, a detritus food chain is the one where the main source of energy is the dead remains of organisms.

Ans: Detritus food chain is the type of food chain in which the detritus is utilized to a maximum level. Therefore, there is minimum wastage of organic material. Thus, in a detritus food chain, the primary source of energy is dead organic matter, that includes leaf debris, plant parts and dead animals.

As an example, a grazing food web has plants or other photosynthetic organisms at its base, followed by herbivores and various carnivores. A detrital food web consists of a base of organisms that feed on decaying organic matter (dead organisms), called decomposers or detritivores.

The organisms that consume the primary producers are herbivores: the primary consumers. Secondary consumers are usually carnivores that eat the primary consumers. Higher-level consumers feed on the next lower tropic levels, and so on, up to the organisms at the top of the food chain: the apex consumers.

A food chain follows one path of energy and materials between species. A food web is more complex and is a whole system of connected food chains. In a food web, organisms are placed into different trophic levels.

It is rare to find food chains that have more than four or five links because the loss of energy limits the length of food chains. Therefore, after a limited number of trophic energy transfers, the amount of energy remaining in the food chain cannot support a higher trophic level.