Who’s Who in a
Food Chain?
Food Chain
• A food
chain tells
us what is
eaten by
what in an
ecosystem.
What is an ecosystem?



An ecosystem is all the
animals and the plants
in a habitat, together
with their environment.
An ecosystem provides
everything that the
animals and plants
that live there need.
A rock pool is an
ecosystem, and so is a
forest or a lake.
What does this food chain
show?
The plant is
eaten by the slug.
The slug is eaten
by the frog.
The frog is eaten
by the heron.
• ALL LIVING THINGS
NEED ENERGY
FROM FOOD.
• Green plants are the
only living things that
can make their own
food.
• They are called
producers.
• A food chain always
begins with a producer.
Producers
Consumers
• Animals are
consumers
because they
eat plants or
other animals to
get their
energy.
• The first consumer in a food
chain is an herbivore (an animal
that eats only plants).
• The secondary
consumer is a
carnivore (an
animal that eats
only other
animals).
• A carnivore may
be eaten by a
larger carnivore
called a third/
tertiary
consumer.
Consumers
Consumers
• A food chain
sometimes
includes a
consumer that
is an omnivore
(an animal that
eats both plants
and animals).
Decomposers
• Decomposers are
consumers that
break down dead
plants and
animals.
• They return
materials stored
Then
green
plants
in dead plants
use the materials
and animals to
to make food.
the soil, water,
and air.
This is a beach food chain
Can you describe what is
happening?
Can you show a different food
chain?
• What did each
food chain
begin with?
• Green Plants you say? Yes!
• Almost every food chain starts
with a green plant. IT has to have
chlorophyl to get energy from the
sun.
And where did this green plant gets
it’s energy from?
The Sun
Food
Web:
Shows more
than one
direction of
flow of energy.
Energy flow
 Each animal in the
food chain eats
another animal or a
plant in order to gain
energy.
 The energy flow in
the ecosystem keeps
all of the animals
alive.
At each level only 10% of the original
energy is transferred to the consumer.
Where did the other 90% of energy go?
It became heat and mechanical energy!
Example of Energy Transfer in Joules.
10, 000 algae
• Producer to primary consumer: 16% transferred
• Primary to Secondary Consumer: 8% transferred
• Secondary to Tertiary Consumer: 10% transferred
What people do
• Sometimes, humans cause
problems for the plants
and animals in an
ecosystem.
• Oil spills pollute the sea
and beaches.
• Forests are cut down to
make way for roads, and
so that land is available
for cattle to graze.
What affect does
this have on a
food chain?
Destroys plants and animals in the
Food web so populations can’t come back
Match the words and phrases.
A food chain shows
producers
Most food chains
what is eaten by
start with
what
Plants are
predators
Animals are
prey
Animals that hunt
and eat others are
called
Animals
that are caught and
eaten are called
consume
rs
a green
plant