The Cell Theory was created by Mathias Scheiden and Theodor Schwann and states that all living beings are formed by cells.
The establishment of the Cell Theory was possible thanks to the development of microscopy.
It is currently one of the most important generalizations in biology.
History of Cell Theory
In 1665, Robert Hooke analyzed cork slices under a microscope and observed that they were formed by microscopic cavities, which he called cells.
The word cell comes from Latin, cell, short for cella, small compartment.
Dutch microscopist Antoni van Leeuwenhoek was the first to record free cells.
In 1674 he reported the discovery of the protozoan. In 1677, from human sperm and in 1683, from bacteria.
With the improvement of microscopy, Roberto Brown discovered the cell nucleus in 1833.
In 1838, Mathias Schleiden formulated the principle that all vegetables are made up of cells.
In 1839, this principle was extended to animals by Theodor Schwann.
Walther Flemming, in 1882, observed the appearance of filaments in the nucleus of the dividing cell.
These studies and discoveries were fundamental for the Cell Theory to be established.
Learn more about the study of cells, Cytology.
Postulates of Cell Theory
The modern version of Cell Theory is based on:
- All living things are made up of cells;
- The essential activities that characterize life take place inside cells;
- New cells form by dividing preexisting cells through cell division;
- The cell is the smallest unit of life.
Know more about:
- cells
- Prokaryotic and Eukaryotic Cells
Viruses and Cell Theory
You virus they do not have cells in their constitution, so they are acellular.
Viruses are obligate intracellular parasites.
Despite having no cells, they depend on living cells to carry out their vital activities.
This proves that activities essential to life only occur inside living cells, as postulated by Cell Theory.
See too: Cell Exercises
