Question

A bacterium modifies its DNA by adding methyl groups to the DNA, It does so to

• A. Clone its DNA
• B. Be able to transcribe many genes simultaneously
• C. Turn its gene on
• D. Protect its DNA from its own restriction enzyme

Answer 1

Answer: (D)

Protect its DNA from its own restriction enzyme

• Restriction endonucleases recognize specific sequences in the incoming DNA and digest the DNA into fragments.
• They cut the DNA either at specific sites and are synthesized by bacteria as part of their defense mechanism.
• The restriction sites are very short sequences and can be present in their own DNA.
• Its own DNA is protected from destruction by adding methyl groups to it.
• Only a few specific bases are modified on each strand.

Thus, the correct answer is option D.