1. All living organisms are composed of one or more cells. This means that all life, from the smallest bacteria to the largest whale, is made up of cells.

2. The cell is the basic unit of structure and function in living organisms. This means that cells are not only the building blocks of life, but they also carry out all the essential processes of life, such as metabolism, growth, and reproduction.

3. All cells arise from pre-existing cells. This means that new cells are not created spontaneously, but rather they come from the division of existing cells.

These ideas form the foundation of modern biology and have revolutionized our understanding of life on Earth.