AP BIOLOGY

Detailed explanation-1: -The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory. The first part states that all organisms are made of cells. The second part states that cells are the basic units of life.

Detailed explanation-2: -Theory: Cell Theory Postulate 1: All living things are made of at least one cell. Postulate 2: Cells are the basic unit of life. Postulate 3: All cells come from preexisting cells.

Detailed explanation-3: -Virchow’s theory stated that just as animals are unable to arise without previously existing animals, cells are unable to arise without previously existing cells. The idea that new cells arose from pre-existing cells in both diseased and healthy tissue was not original.

Detailed explanation-4: -The three tenets of the cell theory are: All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.