TeachEngineering
Teach Engineering: Dirty Decomposers
Students design and conduct experiments to determine what environmental factors favor decomposition by soil microbes. They use chunks of carrots for the materials to be decomposed, and their experiments are carried out in plastic bags...
CK-12 Foundation
Ck 12: Biology: Autotrophs and Heterotrophs
[Free Registration/Login may be required to access all resource tools.] Discusses how autotrophs and heterotrophs obtain energy.