CK-12 Foundation
Ck 12: Cell Biology
[Free Registration/Login may be required to access all resource tools.] Cells make up all living things but not all cells look alike. This activity introduces cells, cell theory, and the levels of organization in organisms.
CK-12 Foundation
Ck 12: Life Science: Cell Biology
[Free Registration/Login may be required to access all resource tools.] A cell is the smallest structural and functional unit of an organism. Learn more about cell biology in this learning module produced by CK-12.
CK-12 Foundation
Ck 12: Biology: Cell Biology
[Free Registration/Login may be required to access all resource tools.] Introduces cells, cell theory, and the levels of organization in organisms.
Other
Miami University: Cellular Nature of Life?
Basic information about cells in an outline form. Gives good information in an abbreviated format.