Question: what are the 3 parts of the cell theory who came up with it?
Answer: The three main parts are: 1) All living things are made of cells and their products, 2) New cells are created by old cells dividing into two, and 3) Cells are the basic building units of life. In 1665, Robert Hooke observed, with the aid of a crude compound microsope, the structure of a thin slice of cork.