This lesson demonstrates your understanding of the cell theory. The historic cell theory states that living organisms are made of cells, that cells are the basic unit of structure/organization, and that cells come from pre-existing cells. But before this theory became universally accepted, there were important events, people, and controversies that happened. And to give us more depth in completing the puzzle in the wacky history of cell theory, let us all learn from this lesson and after going through it, this competency is expected: Explain the postulates of the cell theory (STEM_BIO11/12-Ia-c-1)