The viral proteins and nucleic acid molecules within the bacterial host assemble spontaneously into up to a hundred new phage particles. Eventually the bacterium lyses, releasing the particles. Lysis can be readily observed in bacteria growing on a solid medium, where groups of lysed cells appear as clear areas, or plaques. In this state, known as lysogeny, the information contained in the viral nucleic acid is not expressed. A lysogenic bacterial culture can be treated with radiation or mutagens, inducing the cells to begin producing viruses and lyse.
Lysogenic phages resemble bacterial genetic particles known as episomes .
The phages have been much used in the study of bacterial genetics and cellular control mechanisms largely because the bacterial hosts are so easily grown and infected with phage in the laboratory. Phages were also used in an attempt to destroy bacteria that cause epidemic diseases, but this approach was largely abandoned in the 1940s when antibacterial drugs became available. Get quality answers at the right price. Listing from Electric Library , a pay service. No relevant pictures or maps found.