Virus

Virus is the formation or structure that consists of a single strand of nucleic acid that is involved in protein coat. Most of them are visible only with an electron microscope. There is a virus that can not be displayed correctly. This virus is not technically considered living organisms because of lack of biological precesos as metabolism and respiration, and can not be played by itself, but requires a host cell to reproduce. Therefore, it is an obligate parasite of the cell.

 When a virus invades a cell was first fixed specific receptors on the cell membrane, which has an affinity, to destroy penetrate inside the cell. After that, you can not prove their existence in any way to the top for a while. It is concluded that disintegrate into its constituent elements, which was multiplied by the metabolic processes of cells to join later in greater numbers and become the basic cells. The virus can pass through the two daughter cells when a cell divides, spreading defined by this mechanism.