Question

what is cell theory ? who formulated it ?

Answer 1

The Cell Theory states:

1. All living organisms are composed of cells. They may be unicellular or multicellular.
2. The cell is the basic unit of life.
3. Cells arise from pre-existing cells. (They are not derived from spontaneous generation.)

It was formulated by Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow.

Answer 2

Cell theory was formulated bySchielden and Schawann
Cell theory
that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. 
hope it will help u