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Assertion (A): Primary transcripts in eu...

Assertion (A): Primary transcripts in eukaryotes are non-functional.
Reason (R) Methyl guanosine triphosphate is attached to 5'-end of hnRNA.

A

Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A)

B

Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).

C

Assertion (A) is true but reason (R) is false.

D

Assertion (A) is false but reason (R) is true.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the assertion and reason provided, we will analyze both statements step by step. ### Step 1: Understand the Assertion **Assertion (A)**: "Primary transcripts in eukaryotes are non-functional." - In eukaryotic cells, the primary transcript (also known as heterogeneous nuclear RNA or hnRNA) includes both exons (coding sequences) and introns (non-coding sequences). - Before the primary transcript can be translated into a protein, it must undergo several processing steps, including splicing (removal of introns), capping, and polyadenylation. - Therefore, the primary transcript is considered non-functional until it is processed into mature mRNA. **Conclusion**: The assertion is **correct**. ### Step 2: Understand the Reason **Reason (R)**: "Methyl guanosine triphosphate is attached to the 5'-end of hnRNA." - The methyl guanosine cap (7-methylguanylate) is indeed added to the 5' end of the primary transcript during the capping process. - This capping is crucial for mRNA stability, export from the nucleus, and initiation of translation. - However, the presence of the cap does not directly explain why the primary transcript is non-functional. The primary transcript's non-functionality is primarily due to the presence of introns, which need to be removed. **Conclusion**: The reason is **correct**, but it does not explain the assertion adequately. ### Step 3: Evaluate the Relationship Between Assertion and Reason - Both the assertion and the reason are correct statements. - However, the reason does not provide a valid explanation for the assertion. ### Final Answer Based on the analysis above, the correct answer is: **Option 2**: Both are correct, but the reason is not explaining the assertion correctly. ---
To solve the question regarding the assertion and reason provided, we will analyze both statements step by step. ### Step 1: Understand the Assertion **Assertion (A)**: "Primary transcripts in eukaryotes are non-functional." - In eukaryotic cells, the primary transcript (also known as heterogeneous nuclear RNA or hnRNA) includes both exons (coding sequences) and introns (non-coding sequences). - Before the primary transcript can be translated into a protein, it must undergo several processing steps, including splicing (removal of introns), capping, and polyadenylation. - Therefore, the primary transcript is considered non-functional until it is processed into mature mRNA. ...
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