Question

.................. is the natural defence of bacteria against invading phages.

• A. Prophages
• B. Interferons
• C. Restriction enzymes
• D. All of the above

Answer 1

The correct option is A Prophages

A prophage is a bacteriophage genome which is inserted and integrated into the circular bacterial DNA chromosome or existing as an extrachromosomal plasmid. This is a latent form of a phage, in which the viral genes are present in the bacterium without causing disruption of the bacterial cell. Sometimes prophages may provide benefits to the host bacterium while they are dormant by adding new functions to the bacterial genome in a phenomenon called lysogenic conversion. Examples are the conversion of harmless strains of Corynebacterium diphtheriae or Vibrio cholerae by bacteriophages to highly virulent ones, which cause Diphtheria or cholera, respectively