EVERYDAY SCIENCE

Detailed explanation-1: -All of the interconnected and overlapping food chains in an ecosystem make up a food web. Organisms in food webs are grouped into categories called trophic levels. Roughly speaking, these levels are divided into producers (first trophic level), consumers, and decomposers (last trophic level).

Detailed explanation-2: -All food chains and webs have at least two or three trophic levels. Generally, there are a maximum of four trophic levels. Many consumers feed at more than one trophic level. Humans, for example, are primary consumers when they eat plants such as vegetables.

Detailed explanation-3: -The first and lowest level contains the producers, green plants. The plants or their products are consumed by the second-level organisms-the herbivores, or plant eaters. At the third level, primary carnivores, or meat eaters, eat the herbivores; and at the fourth level, secondary carnivores eat the primary carnivores.

Detailed explanation-4: -Consumers may be identified by their position in a chain: first order (primary) consumers eat producers; second order (secondary) consumers eat primary consumers; third order (tertiary) consumers eat secondary, and so on along a chain.

Detailed explanation-5: -The network of feeding interactions is called a food web.