<P> The difference between lysogenic and lytic cycles is that, in lysogenic cycles, the spread of the viral DNA occurs through the usual prokaryotic reproduction, whereas a lytic cycle is more immediate in that it results in many copies of the virus being created very quickly and the cell is destroyed . One key difference between the lytic cycle and the lysogenic cycle is that the lysogenic cycle does not lyse the host cell straight away . Phages that replicate only via the lytic cycle are known as virulent phages while phages that replicate using both lytic and lysogenic cycles are known as temperate phages . </P> <P> In the lysogenic cycle, the phage DNA first integrates into the bacterial chromosome to produce the prophage . When the bacterium reproduces, the prophage is also copied and is present in each of the daughter cells . The daughter cells can continue to replicate with the prophage present or the prophage can exit the bacterial chromosome to initiate the lytic cycle . </P> <P> Bacteriophages are viruses that infect and replicate within a bacterium . Temperate phages (such as lambda phage) can reproduce using both the lytic and the lysogenic cycle . Via the lysogenic cycle, the bacteriophage's genome is not expressed and is instead integrated into the bacteria's genome to form the prophage . Since the bacteriophage's genetic information is incorporated into the bacteria's genetic information as a prophage, the bacteriophage replicates passively as the bacterium divides to form daughter bacteria cells . In this scenario, the daughter bacteria cells contain prophage and are known as lysogens . Lysogens can remain in the lysogenic cycle for many generations but can switch to the lytic cycle at any time via a process known as induction . During induction, prophage DNA is excised from the bacterial genome and is transcribed and translated to make coat proteins for the virus and regulate lytic growth . </P> <P> The model organism for studying lysogeny is lambda phage . Prophage integration, maintenance of lysogeny, induction, and control of phage genome excision in induction is described in detail in the lambda phage article . </P>

An example of lysogenic conversion by a temperate phage is