Final answer:
A temperate bacteriophage has two life cycles, lytic and lysogenic. The lytic cycle leads to host cell lysis, while lysogenic cycle involves DNA integration and replication with the host's genome without immediately harming it. Environmental stress may switch the cycle from lysogenic to lytic.
Step-by-step explanation:
The life cycle of a temperate bacteriophage includes two primary pathways: the lytic cycle and the lysogenic cycle. In the lytic cycle, the phage DNA replicates independently of the host cell's DNA, eventually causing the cell to burst and release new phage particles. During the lysogenic cycle, the phage DNA integrates into the bacterial chromosome as a prophage, which is then replicated along with the host DNA during cell division, without causing harm to the host cell. Environmental stressors can trigger a prophage to exit the lysogenic state and initiate the lytic cycle, leading to the lysis of the host cell.
Notable pathogens like Vibrio cholerae and Clostridium botulinum can undergo lysogenic conversion when infected by a prophage carrying toxin genes, potentially altering the virulence of these bacteria. This remarkable adaptive mechanism allows temperate bacteriophages to maintain a stable relationship with their host or to enter a destructive phase under certain conditions.