1. The Flow of Energy
* The sun is the primary source of energy for Earth.

2. Energy Pyramid
There is a decreasing amount of energy as it passes through each level. Only about 10% of the energy from each level passes on to the next level. What happens to the other 90%?

3. Food chains show a linear relationship
The arrows point the direction of the flow of energy.
Food chains show a linear relationship
– much like a metal chain with links.

4. Food Web
Food webs are complex and stable – especially when compared with food chains. Why?
Again, the arrows point the direction of the flow of energy.