Ecosystems Food Webs Energy exchange
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Transcript of Ecosystems Food Webs Energy exchange
Ecosystems Food Webs
Energy exchange
Questions• Which of the following would represent a good
investigative experiment testing for affects of a drug on pregnancy?
• 1) A pregnant mouse given 1 ml of a drug and a non-pregnant mouse given 1 ml of a placebo.
• 2) A pregnant mouse given 1 ml of a drug and a non-pregnant mouse given 1 ml of a drug.
• 3) A pregnant mouse given 1 ml of a placebo and another pregnant mouse given 1 ml of a drug.
• 4) A non- pregnant mouse given 1 ml of a drug and a non-pregnant mouse given 1 ml of a placebo.
Ecosystems
• On a blue index card: Write down a definition of an ecosystem. Time limit is 2 minute.
• Pair-Share your definition and then on a green index card write a shared definition between you and your partner.
Ecosystems
• A community of organisms (i.e. plants and animals) living together with their environment (non-living aspects), functioning as a unit.
Energy Flow, Nutrient
Cycling, & Feeding
Relationships
•Nutrients (purple) neither enter nor leave cycle
•Energy (yellow) is not recycled
–Captured by producers
–Transferred through consumers (red)
–Each transfer loses energy (orange)
Primary Productivity: Photosynthesis
• Life uses < 0.03% of the sun's incident energy
• Most is lost as heat from respiration
EnergyEnergyfromfrom
sunlightsunlight
COCO22 absorbed absorbedfrom airfrom air
OO22 released released
to airto air
HH22OO absorbed absorbedfrom soilfrom soil
PhotosynthesisPhotosynthesisSugarSugarsynthesizedsynthesized
MineralsMineralsabsorbedabsorbedfrom soilfrom soil
GrowthGrowth
Colored index cards
• Use a purple index card. It has been said that all flesh is grass. Explain in a couple of sentences why that statement could be true.
Food Chains• (a) A simple terrestrial
food chain.
• (b) A simple marine food chain.
• 10% law determinesthe population sizeof each trophic level
• More organisms at lower trophic levels
A Food Web•Simple food web on a short-grass prairie
•Numbers represent trophic levels
11
1122
22
22
2222
22
2222
33
33
33
33
3333 44
44
44
1=producer2=primary
consumer3=secondary
consumer4=tertiary
consumer
Energy Transfer and LossHeatHeat
HeatHeat
ProducerProducer
PrimaryPrimaryConsumerConsumer
SecondarySecondaryConsumerConsumer
DetritusDetritusFeedersFeedersHeatHeatHeatHeat
ChemicalsChemicalsChemicalsChemicals
Energy transfer
• Only 10% of the total energy is used at each level
– In other words if a producer has 100 calories of useable energy then an herbivore has only 10 calories of useable energy and a carnivore only has 1 calorie
An Energy Pyramid for aPrairie Ecosystem: The 10% Law
Food web exercise• Grab a name tag• Wait for instructions• Producers = candy
– Dinoflagellates=tootsie rolls– Green algae=butter toffee– Diatoms=hard candy– Brown algae=butterscotches
• Consumers– Primary=Turquoise– Secondary=dark green– Tertiary=Fluorescent green
• Primary pickup as many candy as possible in 30 seconds• Secondary tag as many producers as possible• Tertiary tag as many secondary
Food web exercise• Goal: ?• 10 % rule• Modify for fourth graders?
Questions
Which of the following statements best describes the movements of energy through an ecosystem?– 1. Energy flow through
– 2. Energy cycles
– 3. Energy increases
– 4. Energy recycles
Questions
• The amount of life that can be supported by an ecosystem is determined by the
• 1) Efficiency of the consumers
• 2) Number of producers and their efficiency
• 3) Number of heterotrophs and their efficiency
• 4) Number of decomposers and their efficiency
Questions
• If a wolf eats a rodent that ate a smaller insect that ate a plant, the wolf would be a(n):
• 1) primary consumers
• 2) decomposers
• 3) producers
• 4) secondary consumers
• 5) tertiary consumers