What are the four parts of cell theory?

Question

My science teacher asked us to find the four parts of the cell theory. I can only find 3. He said the last would be hard to find.

Answer 1

I think there is the back wall with the toilet.  There are the two side walls with a killer on one side and a rapist on the other and both want a piece of you.  Then there is the locked gate which may or may not be locked and it is guarded by a prison guard who may or may not be a prison guard.  That would be the four parts of the cell.  Good luck on your test.

Answer 2

The four parts of the cell theory are:

1) All living things are composed of cells and cell products.

2) New cells are formed only by division of preexisting cells.

3) All cells are basically similar in chemical makeup and in metabolic activities.

4) The activity of an organism is due to the collective activities and interactions of all of its cells.