Describe the lysogenic cycle.
Answers
The lysogenic cycle is a method by which a virus can replicate its DNA using a host cell. Typically, viruses can undergo two types of DNA replication: the lysogenic cycle or the lytic cycle. ... A bacteriophage, or bacteria virus, injects its DNA into the bacteria.
Answer:
The ability of some phages to survive in a bacterium as a result of the integration of their dna into the host chromosome. The integrated dna is termed a prophage. A regulator gene produces a repressor protein that suppresses the lytic activity of the phage, but various environmental factors, such as ultraviolet irradiation may prevent synthesis of the repressor, leading to normal phage development and lysis of the bacterium. The best example of this is bacteriophage lambda.
Steps:
i) A bacteriophage virus infects a bacteria by injecting its DNA into the bacterial cytoplasm , or liquid space inside of the cell wall .
ii) The viral DNA is read and replicated by the same bacterial proteins that replicate bacterial DNA.
iii) The viral DNA can continue using the bacterial machinery to replicate, or it can switch to the lytic cycle. If the viral DNA stays in the lysogenic cycle, one copy, or few copies, of the DNA exist in many bacteria. In the lysogenic cycle, the DNA only gets replicated when the bacteria are replicating their own DNA.
iv) Eventually, the viral DNA will switch to the lytic cycle, in which the bacterial mechanisms are used to produce lots of DNA and lots of capsids, or protein covers, for the DNA.
v) These capsids get released into the environment, infect a new bacteria, and the lysogenic cycle may start again. If the bacteria is weak or dying, the virus may enter straight into the lytic cycle, in order to avoid dying with the bacteria.