The three parts of the cell theory are as follows:
(1) All living things
are made up of cells,
(2) Cells are the smallest units (or most basic
building blocks) of life, and
(3) All cells come from preexisting cells
through the process of cell division.
Cells were first seen and or observed by the
natural philosopher Robert Hooke in the year 1665.
Hopefully this helped ^.^ please mark brainly