Question

In animal cells, the endogenously produced miRNAs silence gene expression by

• A. base pairing with the 3'-untranslated region of specific mRNAs
• B. blocking mRNA synthesis
• C. binding to the operator site
• D. base pairing with the 3' region of specific rRNAs

Hint:

MiRNAs regulate gene expression by binding to the 3' UTR of target mRNAs, leading to mRNA degradation or translation inhibition.

Answer 1

The Correct Option is A

In animal cells, miRNAs (microRNAs) function by binding to the 3'-untranslated region (3' UTR) of specific mRNAs. This binding can result in the silencing of gene expression through mRNA degradation or inhibition of translation. Therefore, the correct option is (A).
- Option (B) is incorrect because miRNAs do not block mRNA synthesis directly, they affect mRNA after its synthesis.
- Option (C) is incorrect because miRNAs do not bind to the operator site, which is more relevant to bacterial gene regulation.
- Option (D) is incorrect because miRNAs typically interact with mRNAs, not rRNAs.
Thus, the correct answer is (A).