Transcript Food Chains and Food Webs - Kent City School District

Food Chains
and
Food Webs
What is a Food Chain?
A food chain is the path by
which energy passes from
one living thing to another.
What’s in a Food Chain?
Producers
Consumers
Decomposers
Producers
Producers make
their own food
Green plants use
energy from the
sun to make food
Producers are on
the bottom of the
food chain
Autotrophs
 Producers are also called autotrophs
because they produce all of the food that
other organisms use.
Autotrophs
Consumers
Consumers hunt, gather,
and store food because they
cannot make their own.
Heterotrophs
Organisms that do not make
their own food
Another term for heterotroph is
consumer because they
consume other organisms in
order to live
Ex. Rabbits, Deer, Mushrooms
Heterotrophs
Four Types of Consumers
Herbivores
Carnivores
Omnivores
Scavengers/
Detritivores
Herbivores
Animals who eat plants
such as:
– grasshoppers
– rabbits
– squirrels
– deer
– pandas
Carnivores
Animals who only eat other
animals such as:
– tigers
– lions
– hawks
– wolves
– cougars
Omnivores
Animals who eat both plants
and animals such as:
– humans
– bears
Scavengers/Detritivores
Feed on the tissue of dead
organisms (both plants and
animals)
• Ex. – Vultures, Crows, and Shrimp
Decomposers
Microorganisms that are able
to break down large
molecules into smaller parts
Decomposers return the
nutrients that are in a living
thing to the soil
 Ex: Bacteria,fungus
Let’s Look at a Food
Chain
A food chain is a simplified way
to look at the energy that
passes from producers to
consumers.
What is a Food Web?
Most organisms eat more
than JUST one organism
When more organisms are
involved it is know as a FOOD
WEB
Food webs are more complex
and involve lots of organisms
Food Webs
How many food chains can you
make from this food web?
Food Web
Notice that the direction the
arrow points 
The arrow points in the direction
of the energy transfer, NOT “what
ate what”
Trophic Levels
Each step in this transfer of
energy is know as a trophic
level
– The main trophic levels are producers,
consumers, and decomposers
Ecological pyramid
•
•
•
•
Which
Which
Which
Which
level
level
level
level
has
has
has
has
the
the
the
the
most energy?
most organisms?
least organisms?
least energy?