Question

Why is a food web a more realistic way of portraying an ecosystem than a food chain?

Answer 1

Hint: A food web comprises all the food chains in one ecosystem. Each living organism in an ecosystem is a part of multiple food chains. In each food chain direct transfer of energy between organisms occurs. The study of the food chain and food web is useful in understanding the environmental pressure exerted by natural and man-made factors on ecosystems.

Complete answer:
Organisms in food webs are grouped into different trophic levels. The trophic levels are producers, consumers and decomposers. A food web portrays an ecosystem in a more realistic way than a food chain because food chains are so simple. Food chains imply that organisms eat only one type of food which is rarely true.
Food webs provide accurate information about the complexity of feeding relationships in an ecosystem whereas food chains are just linear diagrams that display feeding relationships between a few organisms. Food webs are more complicated and are not purely linear.
Study of food webs is very useful for scientists to find out the bioaccumulation of pollutants up a particular food chain. The accumulation of pollutants can alter the food chain and cause massive shifts in the whole ecosystem (for example, algae blooms).

Note:
The trophic levels in a food web or chain can be classified as producers, consumers and decomposers. Producers make their own food through a process called photosynthesis and depend on any other organisms for nutrition. Consumers are animals that eat the producers. Decomposers are the last part of food chains. They feed on non-living plant and animal remains. They turn decaying organic material into inorganic material.