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Food Chain: Introduction

A food chain explains which organism eats another organism in the environment. The food chain is a linear sequence of organisms where nutrients and energy is transferred from one organism to the other. This occurs when one organism consumes another organism. It begins with the producer organism, follows the chain and ends with the decomposer organism. After understanding the food chain, we realise how one organism is dependent upon another organism for survival.

The food chain also explains the feeding pattern or relationship between living organisms. Trophic level refers to the sequential stages in a food chain, starting with producers at the bottom, followed by primary, secondary and tertiary consumers. Every level in a food chain is known as a trophic level.

The food chain consists of four major parts, namely:

• The Sun: The sun is the initial source of energy, which provides energy for everything on the planet.

  
  

• Producers: The producers in a food chain include all autotrophs such as phytoplankton, cyanobacteria, algae, and green plants. This is the first stage in a food chain. The producers make up the first level of a food chain. The producers utilise the energy from the sun to make food. Producers are also known as autotrophs as they make their own food. Producers are any plant or other organisms that produce their own nutrients through photosynthesis.

  
  

• Consumers: Consumers are all organisms that are dependent on plants or other organisms for food. This is the largest part of a food web, as it contains almost all living organisms. It includes herbivores which are animals that eat plants, carnivores which are animals that eat other animals, parasites that live on other organisms by harming them and lastly the scavengers, which are animals that eat dead animals’ carcasses.

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Here, herbivores are known as primary consumers and carnivores are secondary consumers. The second trophic level includes organisms that eat producers. Therefore, primary consumers or herbivores are organisms in the second trophic level.