A typical virus has proteins on its capsid that bind to the outer membrane of the host cell. In the place where the virus adhered viral proteins act to break the cell membrane and then the virus injects its DNA molecules into the host cell. Within the host cell the viral DNA is transcripted and thus messenger RNA is produced. Viral mRNA then is translated and viral proteins are made. Viral polypeptides made within the host cell are cut by enzymes called proteases and then copies of the virus are assembled with the newly formed proteins. When the assemblage of new viruses is completed the cell membrane breaks and the viruses are released to the outside. One sole infected cell can produce hundreds of viruses.   _{Your Comment}