* Robert Hooke: He was the first to observe and name cells in 1665. He looked at thin slices of cork under a microscope and noticed small, box-like compartments which he called "cells" because they reminded him of the cells in a monastery.
* Matthias Schleiden and Theodor Schwann: These scientists built upon Hooke's observations. In the 1830s, Schleiden studied plant cells and proposed that all plants are made up of cells. Schwann, a year later, extended this to animals, concluding that all living things are composed of cells.
While Hooke's discovery of cells was groundbreaking, it was Schleiden and Schwann who laid the foundation for the modern cell theory, which states:
1. All living organisms are composed of one or more cells.
2. The cell is the basic unit of structure and organization in organisms.
3. All cells arise from pre-existing cells.
So, although Hooke's work was essential, it was the combined efforts of Schleiden and Schwann that really established the fundamental principles of cell theory.
