Question

When the phage DNA enters the host bacterium, the host cell protects itself from the viral DNA attacks with the help of ______ enzyme.

Options

• exonuclease

• restriction endonuclease

• DNA ligase

• helicase

Answer 1

When the phage DNA enters the host bacterium, the host cell protects itself from the viral DNA attacks with the help of restriction endonuclease enzyme.

Explanation:

By identifying and cutting particular foreign DNA sequences, these enzymes function as molecular scissors, effectively breaking up the viral DNA before it has a chance to take over the cell. The cell utilises another enzyme to “mask” its own sequences through a process known as methylation in order to stop itself from cutting its own DNA.