Food Chain and Food Web-Notes on Principle and Types!!


Food Chain

food-chainIn every ecosystem , there is a chain of energy. It flows from producer to different level consumers. This chain or system of flowing energy in different trophic level is termed as food chain. In every food chain producers make the food by photosynthesis or chemosynthesis then it flows in primary consumers ar herbivours, then secondary and then tertiary consumers. After that this energy  get back to environment by decomposers and the chain repeats again and again.

Different Trophic Levels

  1. Producer

These are the green belt of a ecosystem. These can synthesis their own food by using inorganic factors  of environment as water, light, minerals etc. They have chlorophyll, where coantosome of thilacoid helps in photosynthesis.

E.g- Photosynthetic plant, Chemosynthetic bacteria etc.

  1. Consumer

These are the animals who cannot make their own food. They feed on producer directly or indirectly.

  1. Primary Consumer

They direct feed on producers .E.g- Cow , Deer, Goat etc herbivour animals.

  1. Secondary Consumer

They feed on primary consumers . E.g- Tiger, Lion etc.

  1. Tertiary Consumer
  2. They feed on both primary and secondary consumers. E.g- Vulture, Peacock etc.

Some Principles of Food Chain 

  1. The flow of energy is unidirectional. The energy of primary consumer cant able to back to producer directly.
  2. One organism can take more than one trophic level. E.g- Man can be primary consumer by eating vegetables, leafs and can also be secondary consumer by eating meat.
  3.  Single ecosystem can have multiple ecosystem at the same time.
  4. The energy being decrease with 10% law in every trophic level.

Types of Food Chain

  1. Grazing Food Chain

This food chain starts with green plant and ends with carnivours.

These are 2 types.

  • Predator food chain

It starts with green plant and end with predator  . The size of organism gradually increases. E.g- Grass>Rodent>Snake

  • Parasitic

Organism size is high to low in different trophic level.

E.g   vegetables>nematodes>bacteria.

Detritus Food Chain

This food chain starts with waste or debris and ends with higher carnivores.

E.g  dead leaf>earthworm>Hawk

Food Web

Interlocking pattern of food chain is called  food web.

A predator from one food chain may be linked to the prey of another food chain.


  1. A typical food web for a terrestrial ecosystem we can see that, a number of food chains operate which ultimately end either at the tertiary consumer level(lion) or at the secondary consumer level (owl).


terrestrial food web

  1. Another example of an aquatic food web in an aquatic ecosystem is given below.aquatic food web


Food Chain And Food Web

There are some difference in between food chain and food web.

Food Chain

  1. A food chain only follows just one path as animals find food.
  2. It is a part of food web.
  3. Energy flows occurs in one way.

Food Web

  1. Food web is several food chains connected together.
  2. It is an assemblage of food chain.
  3. Energy flows through various food chains.

food chain and food webTypes of Food Web

Three different concept of food web has been observed by Paine(1980).

  1. Connectedness Food Web: They are also known as topological food web. Such food web emphasises feeding relationships among organisms, portrayed as a links in the web. It depicts only the presence or absence of atrophic interaction.
  2. Energy Flow Food Web: it sometimes referred to as flow web or as bioenergetics web. Here connections are quantified by the flux of energy between a resource and consumer.
  3. Functional Food Web: Functional food web is also known as interaction food web. That identifies the feeding relationships within the topological food web that are most important to community structure.

types of food web


These three food webs are important of each population in maintaining the integrity of a community.

Thank you.