1. All living organisms are composed of one or more cells. This means that cells are the basic building blocks of all life.

2. The cell is the fundamental unit of structure and function in living organisms. This means that all life processes happen within cells, and cells are the smallest unit capable of carrying out these processes.

3. All cells arise from pre-existing cells. This means that new cells are not spontaneously generated, but are always created by the division of existing cells.