Question

Which of the following statements are correct for micro RNA (miRNA)?
(A). Noncoding RNA
(B). Regulates mRNA function
(C). Involve in gene regulation
(D). miRNAs are found in eukaryotes
Choose the correct answer from the options given below:

• A. (A), (B) and (C) only.
• B. (A), (B) and (D) only.
• C. (A), (B), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

miRNAs act as the cell's dimmers: They fine-tune gene expression post-transcriptionally. They pair with target mRNAs using a 2-8 nucleotide "seed sequence" to suppress protein translation or accelerate mRNA decay.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
MicroRNAs (miRNAs) are small, highly conserved RNA molecules that regulate gene expression post-transcriptionally through RNA interference (RNAi) pathways.

Step 2: Detailed Explanation:
- Statement A is correct: miRNAs are transcribed from DNA but are not translated into protein, classifying them as non-coding RNAs (ncRNAs).
- Statement B is correct: They regulate target mRNA function by base-pairing to complementary sequences (typically in the 3'-UTR of the mRNA), directing its cleavage or translational repression.
- Statement C is correct: By reducing the translation or stability of target transcripts, they serve as key post-transcriptional regulators of gene expression.
- Statement D is correct: miRNAs are transcribed and processed in the nucleus and cytoplasm of eukaryotic organisms, including plants, animals, and some fungi.
- Since all four statements are correct, Option C is the correct choice.

Step 3: Final Answer:
Statements (A), (B), (C), and (D) are all correct.