CK-12 Foundation
Ck 12: Episd: Trophic Levels
[Free Registration/Login may be required to access all resource tools.] Understand what trophic levels are and identify producers and consumers in a food web.
CK-12 Foundation
Ck 12: Episd: Food Webs
[Free Registration/Login may be required to access all resource tools.] A close look at how animals and the environment interact with one another and specifically how the feeding relationships in a food web.