Final answer:
The lytic cycle is a stage in bacteriophage replication wherein the virus injects its DNA into the host, replicates, and directs the production of new viral particles resulting in cell lysis and the release of progeny phages.
Step-by-step explanation:
The lytic cycle is a process in phage replication where the phage nucleic acid is replicated and the phage genes are expressed. This is a multi-step procedure, starting with the bacteriophage attaching to the host cell and injecting its DNA. Shortly after the infection begins, the phage DNA is replicated using the host's cellular machinery.
Concurrently, the expression of phage-encoded endonucleases leads to the degradation of the host's bacterial chromosome, ensuring that the host's resources are redirected towards producing new viral components. These include structural proteins for the capsomeres, sheath, base plates, tail fibers, and viral enzymes necessary for the construction of new phage particles. Polymerase genes, crucial for DNA synthesis, are usually expressed early, while the production of the capsid and tail proteins occurs later.
Once the new virions are assembled during the maturation phase, they will induce lysis of the host cell by employing bacteriophage proteins such as holin or lysozyme to disrupt the bacterial cell wall. The successful completion of the lytic cycle is marked by the release of new mature viruses into the environment, ready to infect new cells.