Viruses are able to infect cells because they share a common <u>genetic</u> code and they use host cell machinery to carry out protein synthesis. Virus infecting a bacteria is called bacteriophage. These bacteriphages can use two different pathways to infect the virus: a) lytiic b) lysogenic. In lytic cycle the virus makes several copies of itself within bacteria and at the end bacterial cell is lysed. In lysogenic cycle virus integrates its DNA into bacterial genome.
