Ecosystems Food Webs Energy exchange

1. Ecosystems Food WebsEnergy exchange

2. 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.

3. 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.

4. Ecosystems • A community of organisms (i.e. plants and animals) living together with their environment (non-living aspects), functioning as a unit.

5. Energy Flow, NutrientCycling, & 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)

6. Primary Productivity: Photosynthesis O2 releasedto air Energyfromsunlight • Life uses < 0.03% of the sun's incident energy • Most is lost as heat from respiration CO2 absorbedfrom air Sugarsynthesized Growth Photosynthesis H2O absorbedfrom soil Mineralsabsorbedfrom soil

7. 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.

8. 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

9. 4 3 4 3 2 2 2 1 2 2 3 1 2 3 3 2 4 3 2 A Food Web • Simple food web on a short-grass prairie • Numbers represent trophic levels 1=producer 2=primary consumer 3=secondary consumer 4=tertiary consumer

10. Energy Transfer and Loss Heat SecondaryConsumer PrimaryConsumer Producer Heat DetritusFeeders Chemicals Heat

11. 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

12. An Energy Pyramid for aPrairie Ecosystem: The 10% Law

13. 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

14. Food web exercise • Goal: ? • 10 % rule • Modify for fourth graders?

15. 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

16. 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

17. 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