Transcript Food Chain - s3.amazonaws.com

AS SOON AS YOU ARE SEATED...
Above is an image of a Food Chain. Using the words below as
a guide, write a passage outlining everything you have learned
about food chains. Do Not Use Your Notes. I will collect these
to gauge the success of last week’s lessons.
Autotroph, Primary Producer, Secondary Consumer,
Trophic Level, Top Predator, Sunlight, Decomposer,
Energy Transfer, 10%
Energy Flow Through
Ecosystems…A REVIEW
Ecosystem and Energy Roles
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Ecosystem: all living & non-living things that
interact in an environment
Energy Role in an Ecosystem
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Determined by:
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How it obtains energy
How it interacts with other living organisms in its
ecosystem
Some Energy Roles
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The sun: provides energy
Producers: harness energy from the sun

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Consumers: organisms that eat something
else
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ex. plants
ex. animals
Decomposers: return energy to the
environment

ex. fungus, bacteria
Producers
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Plants harness energy from the sun through
photosynthesis
They are the base of every food chain

Source of food for all other animals
Consumers
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4 Types
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Herbivore: eats only plants
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Carnivore: eats only meat
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Ex. Polar bear
Onmivore: eats plants and animals
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Ex. Cows, horses
Ex. Humans, grizzly bears
Scavenger: carnivore that feeds on bodies of
dead organisms
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Ex. Vultures
Decomposer
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Decomposers break down wastes and dead
organisms and return the raw materials to the
environment

Ex. Bacteria, fungi
Energy flow through biological systems
Food Chains
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Food Chain: series of events in which one
organism eats another and obtains energy
Food Chains Continued
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Arrows always points in the
direction of energy flow
1st organism is always the
producer
2nd organism is the consumer
that eats the producer
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3rd organism is the consumer
that eats the 1st level
consumer
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
Primary consumer
Secondary consumer
And so on…..
Laws of Thermodynamics!!
Knowledge Check!!
You are a green plant that just created
5,000,000 kJ of energy through
photosynthesis. OH NO!! You’ve just been
eaten by a field mouse. OH NO!! Now, the
mouse has been eaten by a fox. OH NOOO!!
The fox has been eaten by a wolf.

How many kJs of energy did the mouse, fox,
and wolf receive?
Knowledge Check!!
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MOUSE:
FOX:
WOLF:
Now...
Page 32, # 3
500,000 kJ
50,000 kJ
5,000 kJ
1st Law of Thermodynamics
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Energy cannot be created nor destroyed, but
can be transformed from one form to another.
The amount of energy in the universe is
constant.
Approx. 99% of energy on Earth available for
living organisms comes from the Sun.
2nd Law of Thermodynamics

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During any energy transformation, some
energy is converted into unusable energy or
is lost.
No energy transformation is ever 100%
efficient.
Ecological Pyramids!!
Ecological Pyramids
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Can be used to represent energy flow or
matter in food chain and food webs.
Are based on the idea that, due to energy
loss, fewer organisms can be supported at
each additional trophic level in a food chain.
1. Pyramid of Biomass
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Shows the total mass of living tissue at each
level.
Biomass: the total dry mass of all of the
living material in an ecosystem.
2. Pyramid of Numbers
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Shows the number of organisms at each
trophic level.
Number of organisms decreases as we move
up the pyramid.
3. Pyramid of Energy
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The amount of energy at the pyramid bottom
is fixed by the amount of photosynthesis that
occurs.
Most of the energy at each level of a food
chain is lost as heat (90%) which means that
only 10% of energy is useful and is passed
onto the next level.
Sample Energy Pyramid