1.10 Energy Flow and the 10% Rule
Do three things: a photo challenge, a hands-on lab, and a quick check.
Unit 1 · Topic 1.10
Why are there so few lions and so much grass?
Do 1Which has more energy?
Compare two groups. Pick the one with more energy available in the ecosystem.
Do 2Energy pyramid
About 10 percent passes to the next level. The rest is mostly lost as heat.
Now you do the math
Solved0 of 4
Do 3Quick check
Your topic score
Key terms
- 10% rule
- About 10 percent of the energy at one trophic level is passed to the next.
- Energy pyramid
- A diagram showing less energy at each higher trophic level.
- Heat loss
- Cells release energy as heat during respiration, which is why most energy is lost at each step.
- Why chains are short
- So little energy reaches the top that few levels can be supported.
Photo credits
- Cattle on pasture. Photo: USDAgov (Public domain)
- Elk grazing. Photo: Tim Pearce, Los Gatos (CC BY 2.0)
- Grassland. Photo: Jeff Belmonte (CC BY 2.0)
- Lion in dry grass. Photo: George M. Groutas (CC BY 2.0)
- Wheat field. Photo: dolbinator1000 (CC BY 2.0)
- Gray wolf in snow. Photo: U.S. Fish and Wildlife Service - Midwest Region (CC BY 2.0)
Photos are public domain, CC0, or CC BY. Diagrams and data are original to Green Flask Science.
Teaching AP Environmental Science?
The Green Flask Science™ full-year APES bundle covers all nine units with slides, guided notes, original activities, simulations, and quiz and test banks.