Question

Given below is a heterogeneous RNA formed during Eukaryotic transcription:

How many introns and exons respectively are present in the hnRNA?

• A. 7, 7
• B. 8, 7
• C. 8, 8
• D. 7, 8

Hint:

In eukaryotes, hnRNA is the precursor to mRNA and contains both exons and introns. Exons code for proteins, while introns are removed during mRNA processing.

Answer 1

The Correct Option is B

Step 1: In eukaryotic transcription, the RNA produced is initially a heterogeneous nuclear RNA (hnRNA) that includes both introns and exons.
- Exons are the regions that code for the protein.
- Introns are the non-coding regions that are spliced out during the processing of hnRNA to mRNA.
Step 2: Examining the given sequence of hnRNA:
- The diagram shows a sequence where the exons are represented as coding regions (usually shown with larger segments).
- The introns are the non-coding regions that interrupt the exons.
Step 3: Counting the introns and exons:
- From the given sequence, there are 8 exons and 7 introns in the hnRNA.
Step 4: Conclusion:
The correct number of introns and exons are 8 and 7, respectively. Hence, the correct answer is option (B).