Question

A temperate phage

a) May be lysogenic.
b) May be lytic.
c) Enters a lysogenic or lytic life cycle shortly after entering the host cell.
d) Are all RNA viruses.
e) May be lysogenic AND enters a lysogenic or lytic life cycle shortly after entering the host cell

Answer 1

A temperate phage can undergo both lysogenic and lytic cycles, integrating its DNA into the host genome or replicating and causing host lysis. It decides between these pathways based on environmental conditions and interactions with the host.

Step-by-step explanation:

A temperate phage can exhibit both lysogenic and lytic cycles in its lifespan. In the lysogenic cycle, the phage's DNA is integrated into the host's genome, becoming a prophage, and is replicated with the bacterium's DNA, passed to daughter cells. This can result in phenomena such as lysogenic conversion, where the presence of phage DNA changes the bacterial host's phenotype. If the host is subjected to environmental stressors such as starvation or exposure to toxic chemicals, the prophage may be excised from the host genome and enter the lytic cycle, where it replicates, assembles new phage particles, and eventually causes lysis of the host cell to release the new phages.

An example of a temperate phage that can follow these cycles is the lambda phage, which infects Escherichia coli. Hence, a temperate phage's life cycle is not exclusively lytic or lysogenic; it has the potential for both, depending on the environmental conditions and interactions with the host bacteria.