1. All living organisms are composed of one or more cells. This means that cells are the building blocks of all living things, from single-celled bacteria to complex multicellular organisms like humans.
2. The cell is the basic unit of structure and function in living organisms. This means that cells are not only the building blocks, but they also carry out all the essential life processes, such as metabolism, growth, and reproduction.
3. All cells arise from pre-existing cells. This means that new cells are not spontaneously generated, but rather are produced through the division of existing cells.
Therefore, the main parts of the cell theory are:
* 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.
