Here's a breakdown:
* Schleiden's research: He was a botanist who studied plant tissues under a microscope. He observed that all plants, regardless of size or complexity, were composed of basic units called cells.
* Contribution to cell theory: His findings, along with those of Theodor Schwann (who studied animal cells), led to the formulation of the cell theory. This theory states that:
* All living organisms are composed of one or more cells.
* The cell is the basic unit of structure and function in all living organisms.
* All cells arise from pre-existing cells.
Schleiden's work was instrumental in establishing the cell as the fundamental building block of life.
