NEET BIOLOGY

Detailed explanation-1: -The lysogenic cycle: The phage infects a bacterium and inserts its DNA into the bacterial chromosome, allowing the phage DNA (now called a prophage) to be copied and passed on along with the cell’s own DNA.

Detailed explanation-2: -Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium’s genome or formation of a circular replicon in the bacterial cytoplasm. In this condition the bacterium continues to live and reproduce normally, while the bacteriophage lies in a dormant state in the host cell.

Detailed explanation-3: -The lysogenic cycle, or non-virulent infection, involves the virus assimilating its genome with the host cell’s genome to achieve replication without killing the host. Figure 1. Example structure of a bacteriophage. In order to reproduce, phage must first enter the host cell.

Detailed explanation-4: -During the lysogenic cycle, instead of killing the host, the phage genome integrates into the bacterial chromosome and becomes part of the host. The integrated phage genome is called a prophage. A bacterial host with a prophage is called a lysogen.