Food Chains and Food Webs

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Food Chains and Food Webs

• How energy moves in an ecosystem
• OR
• who eats who!?

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• All things in can ecosystem are either abiotic or
  biotic.

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• Biotic factors are grouped by what each organism
  eats.

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• All of the energy in an ecosystem starts with the
  sun.

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• Producers use the sun to get energy and make
  their food through a process called
  photosynthesis.

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• Consumers have to eat producers or other
  consumers to get their energy.

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• Decomposers get energy from eating dead consumers
  and producers.

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• Organisms need this energy to live.
• Energy moves through an ecosystem when one
  organism eats another organism.
• This keeps the ecosystem going.

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This energy pyramid is one way to show how
energy moves. Producers are always at the bottom
of the energy pyramid because they are the first
things eaten. Notice that the amount of energy
is lost, or decreases, as more organisms eat each
other.
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• If we want to show the ways energy moves through
  an ecosystem we use a food chain or a food web.

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• Food Chain A food chain shows one path of how
  energy moves through an ecosystem (who-eats-who).
• Food Web A food web shows many paths of how
  energy moves through an ecosystem (who-eats-who).
  A food web is made up of many different food
  chains.

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Food ChainRemember Arrows are used to show
where the energy is going.
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Food Web Remember Arrows are used to show where
the energy is going.
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• Turn to you partner and tell them everything you
  know about food chains and food webs and what
  they show us about an ecosystem.

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• You could have mentioned that
• It shows use the way energy moves in an
  ecosystem.
• It shows us who-eats-who in an ecosystem.
• It is made up of producers, consumers and
  decomposers.
• Arrows are used to show where the energy is
  moving.
• ?

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• Now turn to your partner and discuss the
  difference between a food web and a food chain.

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• You could have said that
• A food chain shows one way energy moves in an
  ecosystem but a food web shows many ways energy
  moves.
• A food web is made up of many different food
  chains.

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Draw your own food web with the following
organisms ( Dont forget to include arrows and
remember that arrows show where the energy is
moving.)

• Mouse
• Fox
• Owl
• Snake
• Berries

• Rabbit
• Squirrel
• Leaves
• Grasshopper
• Frog