Virus

A virus is a tiny particle. Much smaller than the smallest of cells. It is non living. Viruses are basically a small segment of genetic material, DNA or RNA, that is surrounded by a coating of protein called a capsid.

Unlike cells, viruses do not use energy. They do not grow or respond to changes in their environment. They can only reproduce by infecting other cells. However, like cells, viruses to change, evolve, over time.

Viruses infect cells by injecting their genetic material into this “host” cell. This causes a chain reaction of events that trick the cell into creating millions of copies of the virus. Eventually the viruses burst out from the host cell, destroying it, and spreading to other cells.

T4 Bacteriophage Virus