Virus
Viruses can be released from the host cell by lysis, a process that kills the cell by bursting its membrane and cell wall. This is a feature of many bacterial and some animal viruses. In some viruses  the viral genome is put by genetic recombination into a specific place in the host's chromosome. The viral genome is then known as a "provirus" or, in the case of bacteriophages a "prophage".60 Whenever the host divides, the viral genome is also replicated. The viral genome is mostly silent within the host; however, at some point, the provirus or prophage may give rise to active virus, which may lyse the host cells.chapter 15 Enveloped viruses (e.g. HIV) typically are released from the host cell after the virus acquires its envelope. The envelope is a modified piece of the host's plasma membrane.185/7