Which is a component of the modern cell theory that was not part of the original cell theory? all organisms are made of cells. all cells are similar in composition and metabolic activities. all cells come from preexisting cells. a cell is the basic unit of structure and function for all living things.

            The correct option is that all cells are similar in composition and metabolic activities.
Explanation:
                     The first theory about cell was proposed by two German biologist Theodor Schleiden and Matthias Schwann in 1839. 

Postulates:
                The main postulates of this theory are as follow:
1. Cell is the basic structural and functional unit of living organisms.
3. All living organisms are composed of cells.
3. New cells arise from already pre existing cells by division.

               Modern cell theory is the new version of same cell theory. It also added that all cells are chemically similar in composition and metabolic activities. Cells contain hereditary materials and energy flow occurs with in cell.

3. is true i think i should be right