CK-12 Foundation
Ck 12: Algebra: Direct Variation
[Free Registration/Login may be required to access all resource tools.] Learn how to recognize and write equations of direct variation and try practice exercises. [11:11]
CK-12 Foundation
Ck 12: Plant Cell Structures: Parts of a Plant Cell
[Free Registration/Login may be required to access all resource tools.] Take a tour of a plant cell and see how they differ from animal cells. Also take a look at the unique characteristics that some plants have. [2:57]