This statement is a fundamental principle in biology known as the Cell Theory. It states that:

* All living organisms are composed of cells.

* Cells are the basic unit of structure and function in living organisms.

* All cells arise from pre-existing cells.

This theory applies to all living organisms, including:

* Plants

* Animals

* Fungi

* Bacteria

* Archaea

* Protists

There are no known exceptions to this theory.