Question

question 79
in eukaryotic cells, transcription cannot begin until
○ the two dna strands have completely separated and exposed the promoter.
○ several transcription factors have bound to the promoter.
○ the 5 caps are removed from the mrna.
○ the dna introns are removed from the template.

Explanation:

1. Analyze Option 1: In eukaryotic transcription, DNA doesn't completely separate; RNA polymerase and factors bind to the promoter region without full strand separation. So this is incorrect.
2. Analyze Option 2: Eukaryotic transcription initiation requires transcription factors to bind to the promoter first, then RNA polymerase II (for mRNA) associates. This matches the process.
3. Analyze Option 3: 5' capping occurs after transcription (during RNA processing), not before initiation. So this is incorrect.
4. Analyze Option 4: Intron removal (splicing) is part of RNA processing after transcription, not a pre - transcription event. So this is incorrect.

Answer:

B. several transcription factors have bound to the promoter.