Thanks to the invention of the microscope, a few hundred years ago, cells could be discovered. This fact led to the emergence of the science related to its study: Cytology .
The cell is the structural unit of living beings . Even presenting itself with a microscopic size, about five times smaller than the smallest particle that our eyes can see; it is within it that most reactions and chemical processes responsible for the metabolism of living organisms occur. Another characteristic of this structure is the ability to reproduce, by dividing pre-existing cells .
There are two types of cells : prokaryotic, simpler; and eukaryotic, more complex. Despite sharing the characteristics previously described, they have significant particularities. The prokaryotic cells are found in bacteria and archaea; already the eukaryotic , throughout the rest of living beings, that is, protozoa, algae, plants, fungi and animals. A separate case concerns viruses that, because they are non- cellular , are not considered living beings by some scientists.
Given the above, it is unquestionable the importance of understanding the inherent aspects of the cell , from its composition and functions that it performs; even how, in general, to prepare certain samples of biological material and visualize them under a microscope.