The cell theory , applied to biology, is the one in charge of identifying and describing the properties of cells, holding that living organisms can become unicellular or multicellular, or what is the same, they can become composed of a single cell or several. The cell is considered the basic unit of life, which through a process in which cells are split or divided, gives way to the existence of new cells.
Simply put, the cell theory states that all living things are made up of cells , including all organisms that inhabit planet Earth. Once it was demonstrated, the scientific community was able to understand the processes and dynamics of the cell, the most basic physiological unit of biology.
History
The first and most important thing is to know what the cell theory is. Ancient civilizations began to study different aspects of human life, but it was not until the invention of the microscope in the 17th century that plant cells could be observed for the first time.
Then a great debate arose about what exactly cells were . The Englishman Robert Hooke gave them the name “cellulae”, from the Latin “cell.” For his part, the Dutchman, Anton van Leeuwenhoek, father of biology, was the first to observe protozoa, bacteria and sperm.
In the following years other scientists contributed their own proposals , thus giving rise to the cell theory. The Frenchman Xavier Bichat was the one who defined a tissue as a set of cells with similar function and shape at the end of the 18th century.
Later, in the 19th century, the German Rudolf Virchow was the first to show that cells come from other cells , that is, cell bipartition. Building on these discoveries, the cell theory was the subject of debate throughout the 19th century.
Finally, the French Louis Pasteur tested the theory through his experiments to show that life is not generated spontaneously.
The cell theory
This is one of the basic principles of biology . It was formulated by the German scientists: Rudolph Virchow, Matthias Schleiden and Theodor Schwann. They were the first to postulate the view that living organisms are made up of cells.
Among the most important approaches we find that the DNA or genetic code of individuals passes from one cell to another in the process of cell partitioning .
All cells have the same chemical composition and the energy of the whole body flows thanks to all the cells of the body. The evolution of cell theory shows us the progress of science over time.
This theory is considered by many as a form of biological generalization that in turn supports the theory of evolution and thus unifies a branch of scientific knowledge that what it does is study the origin of life.
The principles on which the cell theory is based are, broadly speaking, the same as those of modern biology:
- Living matter can be nurtured and reproduced by the structures found inside the cell.
- The transmission of biological information from parents to children is what allows the persistence of a certain species.
- Cells unite to form tissues in multicellular organisms.
Postulates of cell theory
Cells are the most important units of living organisms, being microscopic in size and capable of independently reproducing . They have been the result of much research and the principles of cell theory were initially proposed by the Germans Matthias Jakob Schleiden and Theodor Schwann, who made their postulates clear:
- Everything in living beings is made up of cells , or their secretion products. Organisms can have a single cell (unicellular) or more (multicellular).
- All living things have their origin in cells . These do not arise spontaneously, but come from previous ones.
- All vital functions occur within cells or in their immediate environment . The cell is the physiological unit of life.
- Each cell contains complete genetic information , allowing hereditary transmission from generation to generation.
Based on these postulates of the cell theory , we can conclude that the role that cells have in the constitution of life as such is fundamental.
