Answer:
The cell theory was given by Schwann and Schleiden. The fact that cells can be observed in plants, animals, fungi, protists, bacteria and archea comes from one of the postulates of cell theory- All living organisms are composed of one or more cells.
Explanation:
The cell theory initially contained three postulates:
The discovery of cell was made by Robert Hooke. Later after further observations, more points were added to the cell theory like