Interactions Within Ecosystems Grade 7 Unit
Overview of Remaining Unit Ecological Pyramids Building 3D models - lab Pesticides : Poison in Food Chain Water Cycle Landfill – Lab Choosing a waste disposal site Garbage and the community Acid in water Greenhouse simulation - lab
Assessment Labs – 30% 3D model Landfill Greenhouse simulation Debate – 15% Notebook – 10% Quiz – 15%
Scientific Report Purpose: Why are you doing the experiment? What are you trying to learn? Hypothesis : What do you believe will happen? Be specific. Materials : List all materials needed to complete the experiment Observations: Charts, pictures, and words describing what you see, feel or measure Conclusion: What did you learn in the end? Be specific and relate to the purpose. Write a sentence on whether or not your hypothesis was accurate.
Ecological Pyramids
Transfer of Energy
Rule of 10 Each time energy is transferred within an ecosystem, some of the energy is lost. Ex. When mosquitoes take a bite from you it stores very little of the energy available in your blood. Most of the energy is used to survive. Flight alone requires a tremendous amount of energy.
Dragonflies vs Mosquitoes When a Dragonfly eats a mosquito, only about 10% of the energy that came from your blood is passed to the dragonfly. The Dragonfly uses energy in catching the mosquito, eating it, and breaking down the large food molecules to simple nutrients. This means only a very small fraction of the energy from your blood is stored by the dragonfly.
Food Chains in a Graph Ecological Pyramids are a graphical way to show the effects of loss of energy. Each level in a pyramid matches a level of producer or consumer in an ecosystem or food chain. At each level the amount of energy available is less. The # of organisms at each level of the pyramid usually decreases.
Understanding 1. Why is less than 10% of the energy the mosquito gets from its food transferred to the dragonfly? 2. Using your own words, explain why there are usually more producers in an ecosystem than consumers?