Energy Flow Through an Ecosystem
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Transcript of Energy Flow Through an Ecosystem
Energy Flow Through an Ecosystem
Food Chains, Food Webs, Energy Pyramids
•Begins with the SUN
•Photosynthesis
6CO2 + 6H2O + sunlight & chlorophyll C6H12O6 + 6O2
• The chemical reaction by which green plants use water and carbon dioxide and light from the sun to make glucose.
• ENERGY is stored in glucose; glucose is stored as starch.
Organisms that can make glucose during
photosynthesis are called PRODUCERS.
Producers use most of the energy they make for
themselves.
Producers use cellular respiration to supply the energy
they need to live.
CELLULAR RESPIRATION is the chemical reaction that releases the
energy in glucose.
6O2 + C6H12O6 --> 6H2O + 6CO2 + energy
The energy that is not used by producers can be passed on to
organisms that cannot make their own energy.
Organisms that cannot make their own energy are called
CONSUMERS.
Consumers that eat producers to get energy:
• Are first order or primary consumers.
• Are herbivores (plant-eaters).
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Most of the energy the primary consumer gets from the producer
is used by the consumer.
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The rest of the energy either a) moves into the atmosphere
as heat…
…or b) is available for another
consumer.
A consumer that eats another consumer for energy:
• Is called a secondary or second order consumer
• May be a carnivore or an onmivore
• May be a predator• May be a scavenger
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Most of the energy the secondary consumer gets from the primary
consumer is used by the secondary consumer.
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Some of the energy is lost as heat, but some energy is
stored and can be passed on to another consumer.
A consumer that eats a consumer that already ate a consumer:
• Is called a third order or tertiary consumer
• May be a carnivore or a omnivore
• May be a predator• May be a scavenger
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Consumers that eat producers & other consumers
• Are called omnivores• Omnivores eat plants
and animals
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Consumers that hunt & kill other consumers are called predators.The animals that are hunted &
killed are called prey.
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Consumers that eat other consumers that have already died are called scavengers.
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The transfer of energy from sun to producer to primary consumer to secondary consumer to tertiary consumer can be shown in a
FOOD CHAIN.
Another way of showing the transfer of energy in an
ecosystem is theENERGY PYRAMID.
Energy pyramids show
• That the amount of available energy decreases down the food chain
• It takes a large number of producers to support a small number of primary consumers
• It takes a large number of primary consumers to support a small number of secondary consumers
Food Webs:• Are interconnected
food chains• They show the feeding
relationships in an ecosystem
• In a food web, arrows are drawn whichever way the energy is being transferred (ie. from the food source to the animal that is doing the eating).
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Copy the following questions on binder paper (skip lines for answers)
1. What is hexavalent chromium? (Where is it found? What is it used for?)
2. Why is there a public health concern regarding hexavalent chromium (how is the public exposed)?
3. How is it currently regulated in drinking water (in Alameda County)? What is a safe level?
4. What are some examples of chromium contamination? In California?
5. What are the health risks (effects) associated with exposure? Who is affected?
Use the websites of the following agencies to research the answer to your question:
• Water.epa.gov• Nih.gov• Oehha.ca.gov• Acwd.org• Niehs.nih.gov**Print out your sources. Be prepared to
discuss your answers**