In the mid 1600's A scientist named Robert Hoek had discovered cells from a cork tree
These small organisms seem like the rooms monks use that are called cells.
In the mid 1600's after the discovery of cells Anton Von Leeuwenhoek had observerd the cells in a pond and also discovered bacteria.
In the 1800's two scientists had discovered all living organisms are made up of cells
The scientists Matthias Jakob Schleidan Theodore Schwann had discovered plants had cells and animal tissue had contained cells as well leading to the cell theory that all living organisms are made up of cells.