Prophage occurs when?

A prophage occurs when a bacteriophage (a virus that infects bacteria) integrates its genetic material into the host bacterium's chromosome. This integrated viral DNA, called a prophage, can remain dormant and replicate along with the host's DNA during cell division. Under certain conditions, the prophage can become activated, excising itself from the bacterial chromosome and entering the lytic cycle, leading to the production of new viral particles and eventual lysis of the bacterial cell.