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TRANSCRIPT
Biology I: Energy Flow Through an
Ecosystem (part 2)
Food Chains, Food Webs, Energy Pyramids
Agenda – Tues. Oct. 4, 2011
Warm-Up
Lesson
Wrap-Up (Identifying food chains)
Wrap-Up (Identifying producers, consumers, decomposers)
Homework Worksheet
Today’s ObjectivesI will explore energy flow within an
ecosystem.
I will define: ecosystem, herbivores, omnivores, carnivores, food chain, food web, energy pyramid.
I will trace food chains within a food web.
I will classify organisms as: producers, consumers, or decomposers.
Warm-Up1.What do decomposers do?
2.If you ate chicken that previously ate grass, what type of consumer would you be?
3.Where does energy flow ultimately begin?
What is an Ecosystem?
An Ecosystem is all of the living organisms and non-living environment found in a particular place
What is an Ecosystem?
Example: a pond or aquatic ecosystemLiving Things: fish, turtles, algae, insects, bacteriaNon-Living Things: physical and chemical
properties of the pond like the amount of oxygen in the pond and its pH
Trophic LevelEach feeding level in an ecosystem
Each level of a food chain or food web
First Trophic Level: made up of only producers
Trophic LevelSecond Trophic Level:
made up of primary consumers
Herbivores: primary consumers that mainly eat plants
Examples: rabbits and grasshoppers
Trophic LevelThird Trophic Level:
made up of secondary and tertiary consumers
Omnivores: consumers that eat both plants and animals
Examples: humans and squirrels
Trophic Level
Carnivores: consumers that mainly eat other animals
Examples: lions and sharks
Food ChainThe flow of energy from the sun to
producers to primary consumers then to higher order consumers can be shown in a food chain.
Food ChainShows only one path for the flow of
energy in an ecosystem.
Food WebEcosystems have many different types of
food chains.
A food web shows how many different types of food chains are connected.
Food webs show the feeding relationships in an ecosystem.
Example Food Web
Energy PyramidEnergy Pyramids show the energy loss
between trophic levels in an ecosystem.
The flow of energy:
radiant energy (sunlight)
chemical energy (stored in plants)
kinetic energy and heat loss (created as consumers feed on each other)
Energy PyramidThe amount of available energy
decreases up the energy pyramid.
Energy Pyramid
Most of the “lost” energy is released as heat into the environment.
Each trophic level contains fewer organisms.
Why does this make sense?
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How Many Chains are in this web?
copyright cmassengale
Identify the Producers, Consumers, and Decomposers