Food Chain
Who can tell me what a
food chain is?
What is a food chain?
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Shows how each living thing gets its food.
Some animals eat plants and some animals eat
other animals.
For example, a simple food chain links the
trees & shrubs, the giraffes (that eat trees &
shrubs), and the lions (that eat the giraffes).
Each link in this chain is food for the next link.
Food Chain vs. Food Web
Who can tell me what the
difference between a food change
and a food web is?
Chains vs. Webs

A food web
is several
food chains
put together
that show
many
different
organisms
and their
source of
food/energy.
Chains vs. Webs
What is the source of energy for
all food webs?
Producers
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Plants are called producers because they are
able to use light energy from the Sun to
produce food (sugar) from carbon dioxide
and water.
Autotroph: Organism that produces its
own food (plants)
Consumers
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Animals cannot make their own food so they
must eat plants and/or other animals.
They are called consumers.
Consumers
There are three groups of consumers.
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Animals that eat ONLY PLANTS are called herbivores
(or primary consumers).
carnivores that eat herbivores are called secondary
consumers
carnivores that eat other carnivores are called tertiary
consumers
e.g., killer whales in an ocean food web ... phytoplankton
→ small fishes → seals → killer whales
Animals that eat OTHER ANIMALS are called
carnivores.
Heterotroph: Organism that must consume (or
eat) its food (animals).
Decomposers
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Then there are decomposers (bacteria and
fungi) which feed on decaying matter.
Using the simple food chain below to
describe how energy comes from the
sun to the plants and the plants pass
the energy to the organisms that eat
the plants and the process continues.
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Sun
trees
giraffes
lions
The sun provides energy to the tree, the tree
provides energy to the giraffe, and the giraffe
provides energy to the lion.
This is the flow of energy.
Arrange the following into a food web.
(Include arrows and group them by producers, consumers and decomposers)
Ultimate energy source!
Producers: get energy from the sun
Consumers: get energy from producers
Decomposers: Breakdown dead
materials – include fungus and
bacteria
Trophic Level

step in a food chain or food web.
Understanding Level:
1 2 3 4
Define (in your own words):
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__________________________________________________
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Draw:
Carnivore

organism that obtains energy by eating
animals.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Herbivore

organism that obtains energy by eating only
plants.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Omnivore

organism that obtains energy by eating both
plants and animals.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Energy Pyramid

diagram used to show how energy is
distributed in food chains of food webs.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Producer

organism that can capture energy from sunlight
or chemicals and use it to produce food from
inorganic compounds; also called an autotroph.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Consumer

organism that relies on other organisms for its
energy and food supply; also called a
heterotroph.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Decomposer
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organism that breaks down and obtains energy
from dead organic matter.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Food Chain

series of steps in an ecosystem in which
organisms transfer energy by eating and being
eaten.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
Food Web

network of complex interactions formed by the
feeding relationships among the various
organisms in an ecosystem.
Understanding Level:
1 2 3 4
Define (in your own words):
__________________________________________________
__________________________________________________
__________________________________________________
Draw:
In this food chain, the spiders are –
A
B
C
D
producers
primary consumers
competitors
secondary consumers
Wolves and hawks are at the same
trophic level because they –
A
B
C
D
both live on land
are both large mammals
both eat primary consumers
have similar hunting patterns
Which organisms in this food web can be described
as both primary and secondary consumers?
A
B
C
D
Hawks
Weasels
Raccoons
Mice
Energy used by producers in a grassland
food web is provided by —–
A
B
C
D
sunlight
photosynthesis
oxygen
carbon dioxide
In this diagram
of a marine food
web, which term
describes the sea
turtle?
A
B
C
D
Aquatic herbivores
Autotrophic producers
Third-level consumers
Primary decomposers
The diagram
represents different
levels of a marine food
pyramid. Between
which two levels is the
greatest amount of
energy transferred?
A
B
C
D
R and Q
S and R
T and S
U and T
According to this food web, which of the
following are omnivores?
A
B
C
D
Snakes
Rabbits
Mice
Grasshoppers
The diagram shows a standard pyramid of
numbers that indicates the number of individual
organisms in a community. Which of the
following situations would form a pyramid
showing more consumers than producers?
A
B
C
D
A small plot with 500 corn plants and 100 grasshoppers
One pond with 300 producers and one snake
An 11,000 m3 lake with 75 fish and one alligator
One giant oak tree with 10,000 insects and 10 lizards
The diagram above is intended to show
relationships in an ecosystem. What do
the arrows represent?
A
B
C
D
The direction of population migration
Differences in dietary habits
Progressively smaller organisms
The direction of energy flow
Insecticides help humans compete with
insects for a resource. Which resource is
most likely to be preserved for humans
through the use of insecticides?
A
B
C
D
sunlight
water
food
air
In this food pyramid, which level
contains the greatest amount of energy?
A
B
C
D
Tertiary consumers
Secondary consumers
Primary consumers
Producers
Viruses differ from bacteria in that all
viruses –
A
B
C
D
cause insect-borne diseases
can be destroyed by antibiotics
have rigid cell walls
must be reproduced in living cells