Question

Given below are two statements:
Statement I: The cap present at the 5'-end of eukaryotic mRNAs is 7-methyl GTP.
Statement II: The 5' cap of eukaryotic mRNAs is essential for their binding by eukaryotic ribosomes and it also enhances their stability.
In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Hint:

5' cap: 7-methylguanylate (m7G).
Functions: Ribosome binding, mRNA stability, nuclear export.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
Eukaryotic mRNAs undergo post-transcriptional modifications, including 5' capping.
These modifications are essential for mRNA function.

Step 2: Detailed Explanation:
Statement I:
The 5' cap of eukaryotic mRNAs is 7-methylguanylate (m7G) linked via a 5'-5' triphosphate bridge.
This is correctly described as 7-methyl GTP.
This statement is true.
Statement II:
The 5' cap is essential for ribosome binding during translation initiation.
It also protects the mRNA from degradation by exonucleases (enhances stability).
This statement is true.

Step 3: Final Answer:
Thus, both statements are correct, which corresponds to option (A).
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