CK-12 Foundation
Ck 12: Organization of Cells
[Free Registration/Login may be required to access all resource tools.] Discusses how cells are organized in living things and explains the origin and significance of multicellular organisms.
CK-12 Foundation
Ck 12: Biology: Organization of Cells
[Free Registration/Login may be required to access all resource tools.] Learn how multicelled organisms have specialized cells that do specific jobs and single celled organisms exist without the help of other cells.