Question

A phage that invades (attacks) a host cell but does not destroy, it is known as
A) Temperate phage
B) virulent phage
C) Phycophage
D) None of the above

Answer 1

Hint: Temperate phages are bacteriophages which can be used to produce copies of one virus. They are arrested in the lysogenic phase and need an induction process to release the copies of the virus.

Complete answer: A phage that invades (attacks) a host cell but does not destroy is known as temperate phage. Bacteriophages are viruses that infect the cell (host cell) and replicate itself inside the cell. They can have DNA and RNA both as their genetic material. They have a typical mechanism of infection via making only the genetic material penetrate the host cell and also use the host cell machinery to replicate itself. They can also self integrate with the host cell genome and cause mutation in the cells. They either replicate and destroy others too or they just replicate and make only one cell die. There are two types of cycle seen after the induction of viral DNA into the host cell: lysogenic and lytic cycle. The lytic cycle is destroying the infected cell while the lysogenic cycle includes the reproduction of phages inside the cell. Temperate phages have the ability to choose the lysogenic cycle only but require induction to burst the cell for the release of small viruses. They are unlike the other virulent bacteria which chooses the lytic cycle and destroys the cell after invading the host cell.
Thus, the correct answer is option A.

Note: A Temperate phage does not destroy the host cell but it inserts its genetic material to the host’s genome. This technique can only be used to make copies and studies or sequencing can be tedious. Virulent bacteriophage destroys the cell after the invasion.