In this PPT you'll get to know about the food chain, food web. With the help of a video and a case study related to the content.

1. November
2019
Food Chain
Presented By- Sahil
Chakraborty
1820993148

2. • Food chain, in ecology, the sequence of
transfers of matter and energy in the form of
food from organism to organism. Food
chains intertwine locally into a food
web because most organisms consume
more than one type of animal or plant.
• Plants, which convert solar energy to food
by photosynthesis, are the primary food
source. In a predator chain, a plant-eating
animal is eaten by a flesh-eating animal.
• In a parasite chain, a smaller organism
consumes part of a larger host and may
itself be parasitized by even smaller
organisms.
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3. 3
Food Chain

4. • Plants are called producers because they are able to
use light energy from the sun to produce food (sugar)
from carbon dioxide and water. Animals cannot make
their own food so they must eat plants and/or other
animals. They are called consumers.
• Animals that eat only plants are called herbivores.
• Animals that eat other animals are called carnivores.
• Animals and people who eat both animals and plants
are called omnivores.
• Then there are decomposers (bacteria, fungi, and
even some worms), which feed on decaying matter.
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5. Food Web
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• A food web consists of all the food chains in a
single ecosystem. Each living thing in an
ecosystem is part of multiple food chains.
Each food chain is one possible path
that energy and nutrients may take as they move
through the ecosystem.
• All of the interconnected and overlapping food
chains in an ecosystem make up a food web.

6. 6
• One of the earliest descriptions of a food chain was described
by a medieval Afro-Arab scholar named Al-Jahiz.
• The earliest graphical depiction of a food web was by Lorenzo
Camerano in 1880, followed independently by those of Pierce
and colleagues in 1912 and Victor Shelford in 1913.
• Charles Elton subsequently pioneered the concept of food
cycles, food chains, and food size in his classical 1927 book
"Animal Ecology“.
• Elton's 'food cycle' was replaced by 'food web' in a subsequent
ecological text.
Background

7. 7
Food Web

8. 8
Food Chain Food Web
• It refers to a natural system by which
energy is transmitted from one
organism to another.
• Member of higher trophic level feed
upon a single type of organism.
• It does not have any effect on
improving the adaptability and
competitiveness of the organism.
• Example- Carrots ---> rabbit --> snake -
-> eagle
• It consists of a number of
interconnected food chains.
• Member of higher trophic level feed
upon many organisms.
• Food webs improves the adaptability
and competitiveness of the organism.
• Example- A hawk might also eat a
mouse, a squirrel, a frog or some other
animal. The snake may eat a beetle, a
caterpillar, or some other animal. And
so on for all the other animals in the
food chain.

9. 9
Video
https://youtu.be/Cd1M9xD482s

10. 10
Case Study
"Volunteering at The Food Chain gives you a great sense of community and friendship."
"I filled out a volunteer application form because I think that volunteering should be a natural thing that we all
do to reach out to others in the community. I enjoy connecting with people and making a difference in a
small way."
Ever the altruist, Ben, Head of Science at a secondary school, has volunteered with us as a bar staff
member at Reading and Kenwood festivals, a kitchen assistant and a lead host for Eating Together. Here he
comments on the social side of volunteering.
"I love the social aspect of volunteering and I’ve met some of my best friends through fundraising events. I
feel a lot of satisfaction through connecting with other people and you get to meet new volunteers all the
time, depending on what shifts you do. When I’ve volunteered as a Lead Host, you get to spend time talking
to service users which I love and of course, eating a delicious lunch together! I’ve gained a greater
understanding about HIV and have been lucky enough to listen in on some of the talks given by the Dietitian
which are very interesting.
"I would say that volunteering at The Food Chain gives you a great sense of community and friendship. It is
an opportunity to show your kindness and to learn about how connect with others. There are a lot of skills
involved when dealing with a range of different people and I feel I’ve really learnt how to empathies with
people.“

11. 11
News Article
Recently a released report, “Little Fish, Big Impact,” authored by the Lenfest Forage Fish Task Force,
an international team of 13 preeminent marine and fisheries scientists, sheds new light on the
ecological and economical importance of forage fish. The authors, including myself, found that
more than half the diet of many seabirds, marine mammals, and larger fish, such as tuna, cod,
and salmon, consists of forage fish. And, as their food supply has declined, so has the
abundance of these predator species. The report also revealed that the value of forage fish left in
the ocean to support production of larger, commercially important species is twice their value in a net.
Overall, forage fish are worth nearly $17 billion per year to commercial fisheries—$5.6 billion as direct
catch and $11.3 billion as food for larger commercially important fish.
https://www.the-scientist.com/critic-at-large/little-fish-in-a-big-pond-40247

12. 12
• Where do humans fit in the food chain?
• What could happen if you remove an animal from the food
chain?
• Who wrote animal Ecology?
• Any two differences between Food Chain and Food Web?
• Few examples of Secondary Consumers?
Questions

13. THANK YOU!