Catalyst

1
Catalyst

• Based on the food chain shown, what would most
  likely happen to the rat population if another
  predator began eating snakes?
• Is the the change in number 1 biotic or abiotic?
• What could cause a decrease in the grasshopper
  population?

2
Agenda

• Catalyst
• Energy Pyramids PowerPoint
• Making an Energy Pyramid
• Energy Pyramid Project

3
Objectives

• SWBAT distinguish between producers and consumers
  and autotrophs and heterotrophs
• SWBAT identify the category of organisms and
  relative amount of energy represented by each
  trophic level of an energy pyramid
• SWBAT explain how and why energy changes from the
  base to the top of an energy pyramid.

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Energy Pyramids

• Biology

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Organisms and Energy

• All organisms need energy to survive, and they
  receive energy from the food that they produce or
  consume

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Energy Flow

• For an ecosystem to exist, there must have
  constant flow of energy between the organisms of
  that ecosystem

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Energy Pyramids

• Scientists model the flow of energy in an
  ecosystem with an energy pyramid
• Contains different levels of organisms known as
  trophic levels

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To take notes

• Fill in the example energy pyramid

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Producers

• The first trophic level is at the bottom of the
  pyramid
• Organisms at the bottom of the energy pyramid are
  known as producers
• Producers are autotrophsorganisms that use
  energy from the sun to produce food

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Producers

• What are some examples of producers/autotrophs?
• Trees
• Grass
• Berries
• Nuts
• Algae
• Phytoplankton

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Consumers

• All other organisms in the energy pyramid are
  consumers
• Consumers are heterotrophsorganisms that obtain
  energy from the food they consume

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Primary Consumers

• Above producers in the pyramid are primary
  consumers.
• 2nd trophic level
• These are herbivoresorganisms that consume only
  plants.

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Primary Consumers

• What are some examples of primary
  consumers/herbivores?
• Insects
• Rabbits
• Deer
• Mice
• Small fish

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Secondary Consumers

• Above the primary consumers in the pyramid are
  secondary consumers.
• These are carnivoresorganisms that consume other
  animals.

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Secondary Consumers

• What some examples of secondary
  consumers/carnivores?
• Frogs
• Snakes
• Large fish
• Foxes

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Tertiary Consumers

• Above secondary consumers are tertiary consumers.
• These may be carnivores or omnivoresorganisms
  that consume both plants and animals

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Tertiary Consumers

• What are some examples of tertiary consumers?
• Hawks
• Eagles
• Bears
• Humans
• Sharks

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Energy in a Pyramid

• So why do scientists use a pyramid to represent
  energy in an ecosystem?
• How does a pyramid change from bottom to top?
• It gets smaller!
• So does the amount of energy in an ecosystem from
  producers ? high level consumers

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Energy Changes

• The bottom of the energy pyramid (producers)
  contains the greatest amount of energy.
• 100 of energy originally present in the
  ecosystem
• The top (tertiary consumers) contains the least
  amount of energy.
• 0.1 of initial energy
• Energy is lost as heat between trophic levels
• 90 lost as heat between each level
• Only 10 of available energy transferred to next
  level

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Summary
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Energy Pyramid
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Question

• If there is less energy available at higher
  trophic levels, will there be more organisms or
  fewer organisms as you go up?

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Number pyramids Biomass Pyramids

• Number pyramids show the population decreasing at
  higher levels

Biomass pyramids show how much food an organism
needs to consume to meet its needs.
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gtgt Check for understanding

• A biologist finds that there is far more algae (a
  producer) in an ecosystem than anchovy. What is
  the reason for this?

Anchovy is a second-order producer, so there is
less energy available than there is for producers.
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Energy Water Demo
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Example Copy the chain and answer questions in
your notes

• Grass ? Insects ? Rodents ? Owl
• Create an energy pyramid.
• Label each level with the appropriate term and
  trophic level.
• Put the names of each organism in the appropriate
  level.

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• If there is 1500kcal of energy in the grass, how
  much energy will be available for the insects?
• 1500kcal x 0.10 150kcal

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Exit Ticket

1. What level on the energy pyramid shown has the
   greatest amount of energy to transfer to the next
   level?
2. What are the secondary consumers in this example,
   and are they autotrophs or heterotrophs?
3. Which level receives the least amount of energy
   from the producers?
4. Why does the amount of energy decrease as you
   move from the bottom to top of an energy pyramid?