Question

A phage that invades but does not destroy the host known as

• A. Temperate phage
• B. Sexduction
• C. Phycophages
• D. Virulent phage

Answer 1

The correct option is A Temperate phage

Phages (or bacteriophages) are the viruses that infect the bacteria. The phages recognize the host (the bacterium) and bind to its surface and then injects its genetic material inside the host. Inside the host, the phage genome is replicated, transcribed and translated and complete phage particles are then assembled which escape from the host cell to infect other cells. The phages follow two different types of life cycles inside the host depending upon whether they kill the host or not: lytic and lysogenic cycle.

The lytic cycle involves the lysis or rupture of host cell thereby releasing numerous viral progeny.

In lysogenic cycle, the viral genome gets inserted into the host's genome and reproduces as the host replicates. Such type of phage is called "Temperate phages" or "lysogenic virus". It remains integrated into the host's genome and continue to replicate without harming the host cell until it could excise itself from the host's genome and undergo lytic cycle.

Therefore, a temperate phage doesn't kill the host instead it integrates its genetic material in the host's genome and continue to replicate along with the host's genome.

So, the correct answer is A.