What organisms are bacteriophages?

Viruses that infect bacteria are called bacteriophages, and some bacteriophages have been studied in detail in the laboratory (making them one of the viruses we know best).

Two different cycles can be used by bacteriophages to infect their bacterial hosts:

Lytic cycle: the phage infects the bacterium, hijacks it to make many phages, and then kills the cell.

Lysogenic cycle: A phage infects a bacterium and inserts its DNA into the bacterial chromosome, allowing the phage’s DNA (now called a prophage) to be copied and transferred along with the cell’s own DNA.