Question

Which of the following is true regarding the phage lambda, a virus which infects bacteria?
A) In the lytic cycle, the bacteria host replicates viral DNA. passing it on to daughter cells during binary fission.
B) In the lysogenic cycle, The bacterial host replicates viral DNA. passing it to daughter cells during binary fission.
C) In the lytic cycle, viral DNA is integrated into the host genome.
D) In the lysogenic cycle, the host bacterial cell burst. releasing phages.

Answer 1

The Enterobacteria phage is a bacterial virus, also known as a bacteriophage, that infects the bacteria Escherichia coli (E. coli). Esther Lederberg first discovered it in 1950.

Complete answer:
The wild form of this virus has a temperate life cycle that permits it to either lysogenic ally remain within its host's genome or enter a lytic phase in which it kills and lyses the cell to create progeny. Lambda strains with certain mutations are unable to lysogenized cells; instead, they proliferate and enter the lytic cycle after super infecting a cell that has previously been lysogenized.
The virus that infects bacteria is known as the lambda phage. In order to infect bacterial cells, the virus may go through two different cycles. The lytic cycle entails the typical process of viral replication, which includes cell membrane penetration, nucleic acid synthesis, and host cell lysis.
The lysogenic cycle is a type of viral replication in which a bacteriophage's nucleic acid is fused with that of a host. Propagation of the ensuing prophage occurs as a result of this. The viral DNA is passed to the daughter cells as the host cells reproduce.
As a result, option (B) is correct.
A head (also known as a capsid), a tail, and tail fibres make up a phage particle (see image of virus below). The phage's double-strand linear DNA genome is found in the head. The phage particle detects and bonds to its host, E. coli, causing DNA in the phage's head to be expelled into the bacterial cell's cytoplasm through the tail.

Note: Lambda phage is a non-contractile tailed phage, which means it can't 'push' its DNA through a bacterial cell membrane during an infection. It must instead infiltrate the host cell via an existing channel, having adapted the tip of its tail to engage with a specific pore to allow passage of its DNA into the hosts.