Food Chain – Class 10 Biology: Important Questions CBSE Term 2 Exams

Each plant and animal present on the earth is dependent on some other plant or animal species to some level for survival. No matter how big or small they are, it shows the interdependence of each organism. It could be bees collecting pollen from a blossom, plant photosynthesis, deer eating shrub leaves, or lions devouring the deer. It is what a food chain is!

A food chain is a linear sequence representing how one organism is dependent on another organism. It reflects the consumption pattern of organisms for food. It is a sequence through which energy and matter are transmitted from organism to organism in the form of food. It represents organisms’ cooperation and interdependence for nourishment and survival. In an ecosystem, the complexity and length of a food chain vary substantially. 

From the perspective of the CBSE class 10 Biology board exams, the “Food Chain” is an important topic. Students must refer to NCERT Solutions for Class 10 Science for further reference. So, let’s go over some important questions from this topic!

What is a Food Chain?

A food chain represents a series of organisms transporting nutrients and energy in the way of food from one organism to another. The food chain depicts who consumes whom in an environment to ensure existence. The food chain forms a route to transfer back energy into an ecosystem. The’ Producers’ create the energy, which is then transported to the ‘Consumers’ and finally to the ‘Decomposers.’

Examples of Food Chains

There are numerous food chains in the ecosystem. Let’s look at some common examples of the food chain from the bottom-up direction:

Forest Food Chain

Plants and trees are the primary producers in a forest’s ecosystem. Plants are eaten up by deer, while predators such as a tiger depend on deer.

PLANTS → DEER → TIGER

Grassland Food Chain

In a grassland, grass makes its food with the help of light energy from the sun. A grasshopper eats grass, and a frog eats grasshoppers. A snake then hunts a frog, and an eagle hunts a snake.

GRASS → GRASSHOPPER → FROG → SNAKE → EAGLE

Pond Food Chain

The algae or aquatic plants are the producers in ponds, eaten by small fishes and insects. These little insects or fish serve as food for larger fish. Following that, larger fish will be consumed by fish-eating birds or animals, forming a chain.

ALGAE or AQUATIC PLANTS → SMALL FISH → LARGER FISH → BIRDS or ANIMALS

What are the Types of Food Chains?

Food Chains are categorized into ‘Detritus Food Chains’ and ‘Grazing Food Chains.’ Let’s go over the specifics from the bottom-up direction:

Detritus Food Chains

The detritus food chain starts from dead organic produce. Such a food chain includes organisms like algae, bacteria, insects, fungus, mites, protozoa, worms, and other creatures and plants. The decomposers are present at the bottom of the food chain. Fungi, bacteria, protozoans, and other organisms are the principal consumers (detritivores), which transfer energy to larger species such as mice. The larger carnivores, such as frogs and snakes, are the secondary consumers. Following that, larger organisms feed on them, becoming a component of the food cycle.

Grazing Food Chains

The grazing food chain begins with green plants, the ultimate producers. The food cycle then continues through herbivores to predators. At the lowest level of the grazing food chain, the green plants acquire energy through photosynthesis.

The first energy transmission in this type of food chain flows from plants to herbivores. This food chain is based on energy transfer from photosynthetic organisms (autotrophs) to herbivores. Because autotrophs are the foundation of all ecosystems on earth, this food chain is mostly followed by the environment.

What is a Trophic Level?

A trophic level is defined as each level or step of a food chain. Autotrophs, or producers, are the first trophic levels in any food chain. Next to them are the primary and secondary consumers. The last trophic level is the decomposers. These tropic levels of a food chain help comprehend the energy transfer at different levels in the food chain. Students can further take help from NCERT Solutions for Class 10 Science for comprehending this topic.

Producers: Producers (green plants) are organisms that make their food through photosynthesis. Producers include all green plants and a few other species. Here the green plants convert solar energy into various essential nutrients. The producers are often referred to as autotrophs because they synthesise their food with the help of sunlight. Producers are always at the top of any food chain.

Consumers: Consumers are the ultimate organisms that rely on producers (green plants or other autotrophic species) for their nourishment. Herbivores are the principal consumers of green plants. Following that, carnivores consume herbivores, parasites that exist on other creatures by sucking nutrients from the host, and vultures, which are animals that feed on dead animals.

Decomposers: Decomposers are organisms, like vultures, that obtain essential nutrition for survival from dead and decaying organic substances. Decomposers are the final trophic level of any food chain. They transform organic compounds into inorganic compounds, then used to feed green plants.

What is a Food Web?

There are various food chains in an ecosystem. A food web is made up of several interrelated food chains. An organism in an ecosystem can be fed to many other organisms while also being a predator to several other organisms. As a result, several trophic levels become intertwined, generating a complicated food web.

Explain the Flow (Transfer) of Energy in an Ecosystem.

• Each organism requires energy to carry out important functions and grow and repair internal tissues.
• The sun is the primary source of all energy required by all organisms. The autotrophs (producers) use the sunlight to prepare their food through photosynthesis.
• Each food chain reflects a progressive transmission of food and energy from one organism to another.
• Only around 1% of total solar radiation on earth is collected by green plants in an ecological system and transformed into food energy via photosynthesis. This energy is kept as food’s chemical energy.
• According to the second law of thermodynamics, when herbivores (primary consumers) eat green plants, a significant amount of energy is shed as heat to the environment. On average, only 10% of food (energy) is converted by herbivores, utilised by their body. Similarly, the next level of the consumer can access only 10% of the herbivore’s energy. Hence, only 10% of the organic matter and energy present at each trophic level reaches the next consumer level.
• Because the amount of accessible energy decreases with each trophic level, food chains are usually only 3 or 4 levels long, with a maximum of 5 levels.
• In an ecosystem, The producers of an ecosystem are usually present in the highest quantity. The number of organisms at each trophic level decreases in the food chain with moving upward. Understand this topic with NCERT Solutions for Class 10 Science.

Summary

A food chain is a diagram that depicts how matter and energy flow through an ecosystem. Plants are at the fundamental level of any food chain, which produces energy with the help of sunlight, and then it progresses to higher-level organisms such as herbivores. When carnivores eat herbivores, energy is passed from one organism to another. This energy in the food chain is passed from one living organism to another organism in the form of food. 

The food chain includes various trophic levels, primary producers, primary consumers, secondary consumers, and decomposers. As a result, students should comprehend the environment’s ecosystem in terms of plants. Follow NCERT Solutions for Class 10 Science or additional references.  Students will be able to pass their CBSE class 10 Biology board exam with higher grades if they prepare these important food chain questions.

FAQs

1. What is an ecosystem?

An ecosystem can be described as a group of living (biotic) and non-living (abiotic) components interacting in an environment.

As per the great scientist “Eugene P. Odum”:

• An ecosystem is the fundamental unit of ecology, where biotic and abiotic components interact.
• Both of these components are necessary for life’s nourishment.
• An ecosystem is a biosphere’s structural and functional unit.
• It can self-perpetuate.
• An ecosystem is an open system dependent on sunlight for its functioning.
• An ecosystem can be both small and large.
• Sir Arthur Tansley originated the term “ecosystem” (1935).

2. What are the characteristics of the food chain?

These are the characteristics of the food chains:

• A food chain represents the feeding connection between an ecosystem’s living creatures (biotic components). In a food chain, there is continuous consumption between the organisms, which means that one group consumes the other group and is then eaten by some other group of organisms.
• A food chain is unidirectional and progresses straightforwardly.
• In a food chain, energy flows in a linear motion from the sun to autotrophs and then to an array of diverse consumers.
• In most cases, the food chain has three or four trophic levels. A maximum of five trophic levels may exist in a few chains.
• Omnivores can occupy various trophic positions in any food chain.
• As per the second law of thermodynamics, 80-90 percent of energy is lost as heat during the transfer of energy from one organism to another.

3. What is the difference between a food chain and a food web?

The main difference between a food chain and a food web is as follows:

4. What is the importance of the food chain in an ecosystem?

The following functions can illustrate the importance of the food chains:

• It allows food to be transferred from one trophic level to another.
• It gives all necessary information about various living (biotic) components present in an ecosystem.
• It aids in comprehending the interconnections and interconnectedness of various organisms in an ecosystem.
• It creates a channel for the flow of energy in any ecosystem.

Here is the list of examples for various trophic levels present in the ecosystem.

• 2 Trophic Level: PLANTS → MEN
• 3 Trophic Level: PLANTS → GOAT → MEN
• 4 Trophic Level: PLANTS → RABBIT → SNAKE → BEAR
• 5 Trophic Level: PLANTS → INSECTS → FROGS → SNAKE → EAGLE

5. Explain the process of biomagnification.

Sunlight is the source of energy in an ecosystem. It has changed from one state to another. Energy is continuously transmitted through one trophic level to another level in a food chain through continuous eating. At every level of transfer of energy in the environment, most of the energy is lost as heat. Around 10% of available energy is transmitted from each trophic level to another in a food chain. It restricts the number of steps in the food chain to four or five.

Biomagnification is the continuous increase in a hazardous non-biodegradable chemical concentration at successive trophic levels in a food chain.