Food Chain


 
 
Concept Explanation
 

Food Chain

Food Chain: For an ecosystem to work there has to be a flow of energy within it. The organisms of the ecosystem need energy in the form of food. The ultimate source of this energy is the sun. A series of organisms through which food energy flows in an ecosystem is called a food chain. It may also be defined as follows. A food chain in an ecosystem is a series of organisms in which each organism feeds on the one below it in the series.

In a forest ecosystem, grass is eaten by a deer, which in turn is eaten by a tiger. The grass, deer and tiger form a food chain. In this food chain, energy flows from the grass (producer) to the deer (primary consumer) to the tiger (secondary consumer).

Plantsrightarrow Insectsrightarrow wormrightarrow Birdrightarrow Hawk

In a freshwater aquatic ecosystem like a pond, the organisms in the food chain include algae, small animals, insects and their larvae, small fish, big fish and a fish-eating bird or animal. A food chain always begins with producers. Herbivores (plant-eaters) come next in the chain. They are consumed by carnivores (flesh-eaters). A few food chains can be long and may extend to the fourth, fifth or even sixth order of consumers.

Phytoplanktonrightarrow Zooplanktonrightarrow Fish rightarrow Sealrightarrow Shark 

Characteristics of food chain

  • Food chain shows nutritive interaction between living organiisms.
  • It is always straight.
  • There is unidirectional flow of energy.
  • There are usually 3-4 tropic levels in the food chain.
  • Organisms can occupy different positions in different food chains.
  • As per second law of thermodynamics, 80-90% of energy is lost as heat at each tropic level transfer.
  • Sample Questions
    (More Questions for each concept available in Login)
    Question : 1

    The green grass at the bottom of the food chain is also called _____________________

    Right Option : A
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    Question : 2

    Which of the following organisms is the quaternary consumer ?

    Right Option : B
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    Question : 3

    The third trophic level of a grassland food chain can have ___________________-

    Right Option : D
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