UTRs are the untranslated regions present on

Options

A. rRNA
B. tRNA
C. mRNA
D. hnRNA

Answer

**Step-by-Step Solution:**

1. **Understanding UTRs**: UTRs, or Untranslated Regions, are segments of mRNA that do not code for proteins. They are crucial for the regulation of gene expression and play a significant role in post-transcriptional modifications.

2. **Identifying Locations of UTRs**: UTRs are found at two specific locations on the mRNA:
- **5' UTR**: This region is located at the 5' end of the mRNA, before the start codon (AUG). It is also known as the leader sequence.
- **3' UTR**: This region is located at the 3' end of the mRNA, after the stop codon (UAA, UAG, UGA). It is also referred to as the trailer sequence.

3. **Function of UTRs**: UTRs are involved in various regulatory processes, including the stability of the mRNA, the efficiency of translation, and the localization of the mRNA within the cell.

4. **Conclusion**: Based on the definitions and locations of UTRs, we can conclude that UTRs are present on mRNA.

5. **Final Answer**: Therefore, the answer to the question "UTRs are the untranslated regions present on" is **mRNA** (Option C).

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