Question

The predominant mechanism of microRNA mediated regulation of gene expression is inhibition of:

• A. capping of the target mRNA
• B. translation of the target mRNA
• C. polyadenylation of the target mRNA
• D. transport of the target mRNA from nucleus to cytosol

Hint:

MicroRNAs regulate gene expression mainly by inhibiting the translation of target mRNA. They can also lead to mRNA degradation.

Answer 1

The Correct Option is B

Step 1: Understanding microRNA function.
MicroRNAs (miRNAs) regulate gene expression primarily by binding to complementary sequences on target mRNA molecules, leading to either degradation or inhibition of translation.

Step 2: Analyzing the options.
- (A) capping of the target mRNA: Incorrect. miRNAs do not affect the capping of mRNA.
- (B) translation of the target mRNA: Correct — miRNAs typically inhibit translation of the target mRNA, preventing protein synthesis.
- (C) polyadenylation of the target mRNA: Incorrect. Polyadenylation is not directly inhibited by miRNAs.
- (D) transport of the target mRNA from nucleus to cytosol: Incorrect. miRNAs do not affect mRNA transport directly.

Step 3: Conclusion.
The correct answer is (B) because the primary action of miRNAs is the inhibition of translation of target mRNAs.