How Are the Lysogenic and Lytic Cycles Different?

The main difference between the lysogenic and lytic cycles is the outcome of the bacteria. In the lysogenic cycle, the bacteria is preserved and replicates normally. In the lytic cycle, the bacteria is broken apart and destroyed through a chemical process known as lysis.

The lysogenic and lytic cycles are the two life cycles used for replication by a specific group of viruses known as bacteriophages. Bacteriophages are viruses that target and infect only bacteria and can be either temperate or virulent, which are nonlethal and lethal respectively to the bacterial hosts. Temperate viruses follow the lysogenic cycle for reproduction, while virulent cycles follow the lytic cycle.

In the lytic cycle, the bacteriophage injects its viral DNA or RNA particle into the bacterium. The viral particle can attach to a bacterial chromosome and become a prophage, or it can proceed directly to lysis. Either way, the next step in the cycle involves the viral particle replicating at a fast rate until the bacterium's resources are used up and the cell is lysed. The lysogenic cycle begins similarly, with the bacteriophage infecting the bacterium and the viral particles attaching to the bacterial chromosome. Instead of lysing the cell, though, the viral particles replicate as the bacteria replicates through mitosis. Although the lysogenic cycle itself is nonlethal, a lysogenic bacterium may enter the lytic cycle and lyse.