Cell Theory
Before the cell theory it was pre-renaissance. The renaissance was the boom of art and science. So, before the cell theory was religion.
The three contributers to cell theory are Shliden, Shwann, and Virchow.
He said that cells can reproduce cell
Although there is a number of scientific theories, here is a list of ten scientific theories: collision theory, kinetic theory of gases, atomic theory, Big Bang theory, Dynamo theory, cell theory, modern evolutionary synthesis, germ theory, transition state theory, valence bond theory.