The document presents an overview of food chains and food webs, explaining the roles of producers, consumers, and decomposers in energy flow within an ecosystem. It illustrates a simple food chain example and highlights the interconnectedness of food webs, noting that energy transfer decreases at each trophic level. Additionally, it includes questions and a bibliography for further reference.

1. Food Chains
and
Food Webs
Presented By
Group 2: Madhav, Vivaan and Kovid

2. Introduction to Food Chains
A series of organisms in which each creature eats the one below it in the
series and becomes a source of food for the organisms above it.
The Energy Flow in a Food Chain
1 Producers: Plants and Algae
2 Consumers: Animals (Herbivores, Carnivores,
Omnivores)
3 Decomposers: Scavengers and Microorganisms like
Fungi and Bacteria

3. A Simple Food Chain Example
Sun
Energy source
Grass
Producer
Deer
Primary Consumer (herbivore)
Tiger
Secondary Consumer (carnivore)

4. Producers
Producers are the organisms at the base of a food chain that make
their own food, and are also known as autotrophs.

5. Producers are the foundation of all the food chains.
Without producers, there would be no energy for the
rest of the food chain and it would collapse.
Producers are mostly plants, but can also include algae
and some types of bacteria. They use a biochemical
reaction called photosynthesis to convert sunlight into
chemical energy that they use to create organic
molecules, such as glucose, that other organisms can use
as food.
Continued…

6. CONSUMERS
1
Primary Consumers
(Herbivores)
2
Secondary Consumers
(Carnivores/Omnivores)
3
Tertiary Consumers
(Carnivores/Omnivores)
Consumers in a food chain are organisms that eat producers, other
consumers, or both. Consumers are also known as heterotrophs because they
cannot make their own food and rely on other organisms for nutrition.

7. Decomposers
Decomposers are organisms that break down dead organisms and
waste into non-living elements. They are an essential part of the food
chain. Decomposers include bacteria, fungi and snails.
Decomposers are a critical part of the flow of energy through
an ecosystem. Without decomposers, waste would build up in the
environment. They break down dead organisms into simpler materials,
which releases nutrients that plants can use for energy.

8. Introduction to Food WEBS
A food web is a complex network of interconnected food
chains that shows the feeding relationships and energy
transfer within an ecosystem.
Each trophic level (the position it occupies in a
food web) can only pass 10% of its energy to
the next level. This means that there are usually
fewer animals in higher trophic levels because
there is less energy available.

9. AN Example of FOOD WEB
This is an example of a food web in the
ecosystem of Sonoran Desert in USA.
This food web
includes 15
organisms which
are dependent on
each other for
food
This food web
includes 4
producers, 5
primary consumers,
3 secondary
consumers and 3
tertiary consumers

10. R
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Ans:- b) Producers
Answer
Ans:- d) Mouse → Snake → Hawk
SPIN
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Answer
QUESTIONS
Q1) Which of the following has the largest population in a food chain?
a) Decomposers
b) Producers
c) Primary Consumers
d) Secondary Consumers
Q2) Which of the following food chains cannot exist?
a) Green Plants → Deer → Tiger
b) Grass → Rat → Snake → Eagle
c) Marine Algae → Small Fish → Large Fish → Shark
d) Mouse → Snake → Hawk

11. Ans:- 10%
Ans:- 3 (Grasshopper,
Butterfly and Fruit Fly
Answer
Q3) In a food web, each trophic level can only pass __ %
of its energy to the next level.
Q4) How many primary consumers are
there in the given food web?
Answer
R
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SPIN
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12. BIBLIOGRAPHY
• https://en.wikipedia.org/wiki/Food_chain
• https://en.wikipedia.org/wiki/Food_web
• https://byjus.com/biology/overview-of-food-chain/
• https://en.wikipedia.org/wiki/Consumer_(food_chain)
• https://www.britannica.com/science/food-chain
• https://www.google.com/
• https://education.nationalgeographic.org/resource/food-chain/