Many years ago, scientists working with cells developed what is now known as the cell theory. The cell theory states: – All living things are composed of one or more cells. – Cells are the basic units of structure and function in an organism. – Cells come only from the reproduction of existing cells. Which of the following observations best supports the cell theory? Cells come in a variety of shapes and sizes.

Cells have different names for different structures.

Cells can live a very short time.

Cells from animals only create other animal cells.