- If something is made of something else, then that something else can be found in that something
- All living things are made of cells according to the cell theory
- Hence, cells can be found in all living things

So, cells can be found in all living things
Which of the following is found in all living organisms?
- If something is made of something else, then that something else can be found in that something 
- All living things are made of cells according to the cell theory