Cell theory: the theory of our existence
Cell theory is a historic scientific theory which tells us about that inanimate thing does not have but living things do — THE CELL! (Yay)
All living organisms are composed of cells. Anything less than a complete cell is not capable of independent existence.
In this article, we are going to see the developments that led to the making of the cell theory.
Schleiden and Schwann
Matthias Schleiden was a German botanist. He examined a large number of plant and observed that all plants are composed of different kinds of cells which form tissues of the plant (in 1838).
Theodore Schwann was a British zoologist. He studied different types of animal cells and reported that cells have an outer covering (now known as the plasma membrane). He also concluded that the cell wall was an exclusive feature of a plant cell.
Together, Schleiden and Schwann formulated cell thoery:
Drawback: The hypothesis proposed by Schleiden and Schwann could not explain how new cells were formed.
Rudolf Virchow
In 1855, Rudolf Virchow foist explained how the new cells were formed. He said, “ Omnis cellula-e cellula” or new cells were formed from pre-existing cells.
He modified the hypothesis and gave the final shape to the cell theory.
The cell theory that is universally accepted is:
- All living organisms are composed of one or more cells.
- The cell is the fundamental structural and functional unit of life.
- Cells arise from pre-existing cells.
