S1 Science Living Things and The Processes of Life'

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S1 Science Living Things and The Processes of
Life.
Food Pyramids
I. McPhail - 2003
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Energy Loss from a food Chain
From each link of a food chain to the next, about
90 of the energy from the previous link is lost.
Thus only 10 is passed on. By the time a food
chain is four links long, there is rarely enough
energy left to support another link!
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Food Pyramids
We saw earlier how Energy is lost between each
link in a food chain. This can also be
represented as a Food Pyramid, which shows the
relative amount of energy in each link of a food
chain, and the relative population of each
organism.
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Some More on Food Pyramids
Depending on where the animals are in the food
chain, they will be predators, prey, or both.
Predator
Predator Prey
Prey
The green plants are called producers, because
they make food for all the animals
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Some Definitions....

• Producers - Green plants that turn light energy
  into food (chemical) energy.
• Consumers - Any living thing that eats other
  living things for energy.
• Predator - An animal that hunts and eats other
  animals for food.
• Prey - An animal hunted and eaten by a predator.
• Community - All the living things within a
  particular habitat.

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What you should know so far..
So.....

• At each link along any Food Chain, 90 of the
  Energy is lost to the next link.
• So...There are rarely more than four links in any
  Food Chain.
• A Food Pyramid is a diagram showing how Energy
  and the number of organisms changes along a Food
  Chain.
• The Energy in each level decreases as we go up a
  Food Pyramid.
• The number of organisms in each level decreases
  as we go up a Food Pyramid.

End!