Food Chain: Definition, Levels, Examples

Food Chain: There are different types of plants and animals in the ecosystem which interact with each other for different purposes. There is a linear sequence wherein one organism or plant is consumed by the other and this is known as the Food Chain. In technical terms, Food Chain is the sequence through which transfer of energy takes place within a particular ecosystem. The energy transfer is crucial for survival and sustenance of living organisms.

A variety of food chains interlink to form a food web which is the bigger, more complex form of energy transfer sequence. The complexities arise because many organisms consume different other organisms below them in the food chain. The primary food source of the food chain are plants as they use solar energy to produce food through the process of photosynthesis. Students can find the intricacies of the food chain, food web, trophic levels and examples in this article. Read on to find out more.

What is the Food Chain?

A food chain is a sequence of organisms through which nutrients and energy is transferred in the form of food from organism to organism. The food chain describes who eats whom for survival in an ecosystem. The food chain is also the pathway for the transfer of energy in an ecosystem. The energy is produced by the ‘Producers’ and is transferred to the ‘Consumers’ and thereafter to ‘Decomposers’.

Food Chain Examples

The food chain will vary for different ecosystems. let’s go through some food chain examples:

Food Chain in a forest: The producers in a forest ecosystem are plants & trees. The Deer feeds on plants and a carnivore such as tiger feeds on a deer.

Plants —> Deer —> Tiger

Food Chain in a grassland: In a grassland ecosystem, grass produces its own food from sunlight. A grasshopper feeds on grass and a frog feeds on a grasshopper. Thereafter, in the chain, a snake feeds on a frog and an eagle feeds on a snake.

Grass —> Grasshopper —> Frog —> Snake —> Eagle

Food Chain in a pond: The producers in the pond ecosystem can be algae or aquatic plants which are consumed by small insects or small fishes. These small insects or fishes are food for large fishes. Thereafter, fish-eating birds or animals will consume large fish forming a chain.

Algae —> Small Fishes —> large Fishes —> Fish Eating Birds

Food Chain Diagram

This is the food chain diagram for the examples mentioned above:

Trophic Levels

Each step or level of the food chain forms a trophic level. The autotrophs or the producers are the first at the trophic level. Thereafter, Primary consumers and Secondary Consumers follow. The last trophic level is that of the decomposers. These tropic levels help us understand the food chain and transfer of energy in various trophic levels.

Producers: The organisms which produce their own food through photosynthesis are categorised as producers. All the green plants and a few other organisms are classified as producers. The producers utilise solar energy and convert them into nutrients. Producers are also called autotrophs as they prepare their own food. Producers make up the first level in the food chain.

Consumers: Consumers are organisms that are dependent on green plants or other autotrophs for food. The herbivores feed upon green plants and are called the primary consumers. Thereafter, the carnivores eat the herbivores, parasites that live on other organisms by extracting nutrients from the host and lastly the scavengers, which are animals that eat dead animals are part of secondary consumers.

Decomposers: Decomposers are organism that derives nutrients for survival from the dead and decaying organic matter. Decomposers are the last trophic level of the food chain. They convert the organic matter into inorganic materials which provides nutrition to green plants.

Types of Food Chain

Food Chain can be broadly classified into two types namely, ‘Detritus Food Chain’ and ‘Grazing Food Chain’. Let’s go through the details below:

1. Detritus Food Chain: The detritus food chain begins with dead organic matter. Several organisms and plants like algae, bacteria, fungi, protozoa, mites, insects, worms, etc are part of this food chain. The decomposers are at the starting level of this food chain. Organisms like fungi, bacteria, protozoans, etc become the primary consumers followed by larger organisms such as maggots. The secondary consumers are the bigger carnivores like frogs, snakes, etc. Thereafter, other bigger organisms feed upon them to become a part of the chain.
2. Grazing Food Chain: The grazing food chain starts with the green plants as the producers. the cycle thereafter passes through the herbivores to the carnivores. The energy in the lowest level of the grazing food chain is acquired through photosynthesis.

Food Web

In an ecosystem, several food chains exist. Several interconnected food chains form a food web. In an ecosystem, an organism can be prey to several other organisms and at the same time can be a predator for several other organisms. Due to this, many trophic levels get interconnected forming a complex food web. The following image is that of a food web.

Energy Flow in the Ecosystem

Transfer of energy happens at every trophic level. In a terrestrial ecosystem, green plants capture about 1% of the energy of sunlight that falls on their leaves and converts it into food energy. Thereafter, the energy is further transferred to each trophic level. However, at each trophic level, there is a loss of energy in the form of heat to the environment.

10% can be taken as the average value for the amount of organic matter that is present at each step and reaches the next level of consumers. As the energy loss is huge at each step, the food chains generally consist of only three or four steps.

Study Materials on Embibe

Make the use of the following study materials from Embibe which will definitely help you in your exams:

FAQs on Food Chain

Let’s go through the frequently asked questions from below:

Q1. What are animals called in a food chain?
Ans: In general, animals are the consumers in the food chain. The herbivores are the primary consumers and the carnivores are the secondary consumers.

Q2. What is a trophic level?
Ans: Each step or level of the food chain forms a trophic level.

Q3. What’s an example of a food chain?
Ans: A food chain shows you how one organism eats another and transfers its energy. For example, a cow eats grass, and the cow is eaten by humans. The food chain looks like this: Grass – Cow – Humans.

Q4. What food chain are humans in?
Ans: Humans are said to be at the top of the food chain as we eat different types of plants and animals and are not consistently eaten by other animals.

Q5. What is the difference between a food chain and a food web?
Ans: Food Chain is a linear sequence where the trophic levels are well defined. Whereas, the food web is a complex interconnection of the food web.

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