NEETZoologyMolecular Basis of Inheritance
In a eukaryotic transcription unit, the promoter is located towards the 5' end of the coding strand. Which strand's sequence does the newly formed hnRNA resemble, and to which end of this hnRNA are adenylate residues added during post-transcriptional processing?
Options
- ATemplate strand; 5' end
- BCoding strand; 3' end
- CTemplate strand; 3' end
- DCoding strand; 5' end
Correct answer
B. Coding strand; 3' end
Step-by-step solution
During transcription, the DNA strand with 3' 5' polarity acts as the template, while the strand with 5' 3' polarity is the coding strand. The newly synthesized hnRNA is complementary to the template strand, which means its sequence is identical to the coding strand (with uracil replacing thymine). During post-transcriptional processing in eukaryotes, tailing involves the addition of 200-300 adenylate residues to the 3' end of the hnRNA in a template-independent manner. Capping (addition of methyl guanosine triphosp