RNA interference acts by:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Silencing mRNA
RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence. A double-stranded RNA (dsRNA) that is complementary to a particular mRNA binds to that mRNA. It then stops the mRNA from being translated into protein. This is called silencing of the mRNA. RNAi has been used to make tobacco plants resistant to a nematode that attacks their roots.
(1) DNA activation — Incorrect. RNAi acts on mRNA, not on DNA, and it stops a message rather than switching one on.
(2) Lipid synthesis — Incorrect. RNAi has nothing to do with making lipids.
(3) Silencing mRNA — Correct. The dsRNA binds to the matching mRNA and blocks its translation.
(4) Protein degradation — Incorrect. RNAi works before the protein is made. It prevents the protein from being formed; it does not break down a protein that already exists.
NCERT Extract:
Biotechnological Applications in Agriculture – …
