The sequence of eating and being eaten in an ecosystem is known as the food chain. It is the path of transfer of food energy from the producers through a series of organisms i.e herbivores to carnivores to decomposers. There are three basic types of food chain as discussed below:

1.       Grazing food chain

2.       Detritus food chain

3.       Parasitic food chain

1. Grazing food chain: The primary producers are the living green plants which are grazed on by grazing animals. It is found in aquatic and grassland ecosystem.

E.g. of aquatic ecosystem

Phytoplankton →Zooplankton→ Fish→ Hawk

E.g. of grassland ecosystem

Grass→Rabbit→Fox→Wolf→Tiger

Grass→ Grasshopper→ Frog→Snake→Hawk

2. Detritus food chain: This type of food chain starts from dead organic matter and so it is less dependent on solar energy. The dead organic matter is broken down into simple nutrients by microorganisms like fungi and bacteria. This type of food chain is found in forest ecosystem.

Dead organic matter→ Detritivores→Predators

3. Parasitic food chain: In this type of food chain either the producer or the consumer is parasitized and therefore the food passes to the smaller organism. The energy transfer through this kind of food chain is not significant.

Producer→ Herbivores→ Parasite→ Hyperparasites

Trees→ Fruit eating birds→ Lice and bugs→ Bacteria and fungi

Significance of Food Chains and Food webs

1.       They help in maintaining the ecological balance.

2.       They help in understanding the feeding relations among organisms.

3.       Energy flow and nutrient cycling take place through them.

4.       It explains the concept of biomagnification.