How did scientists discover that all living things are made of cells? (2-3 sentences ! ) ((15 points))

The modern cell theory states that all known living things are made up of cells and that the cell is structural & functional unit of all living things.The cell was first discovered and named by Robert Hooke in 1665. He dicover the cells using the new invented microscope. So, the microscope enabled the discovery of cells. Hooke remarked that the cell looked strangely similar to cellula or small rooms which monks inhabited, thus deriving the name.