NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Biology
- Chapter
- Chapter
NEET 2026 · Biology · Chapter
In a bacterial cell, if the σ (sigma) factor becomes...
In a bacterial cell, if the (sigma) factor becomes non-functional, which specific event during transcription will be directly prevented?
Options
- APolymerization of ribonucleotides during elongation
- BBinding of RNA polymerase to the promoter
- CDissociation of the RNA polymerase at the terminator
- DPost-transcriptional capping of the mRNA
Correct answer
B. Binding of RNA polymerase to the promoter
Step-by-step solution
In bacterial transcription, the RNA polymerase holoenzyme consists of a core enzyme and a (sigma) factor.
The core enzyme is responsible for the polymerization of ribonucleotides during the elongation phase.
The factor is essential for the specific recognition of the promoter sequence on the DNA. It allows the RNA polymerase to bind tightly to the promoter and initiate transcription.
If the factor becomes non-functional, the RNA polymerase will not be able to recognize or bind to the promoter region, thereby preventing the initiation of transcription.
Answer: Binding of RNA polymerase to the promoter
The core enzyme is responsible for the polymerization of ribonucleotides during the elongation phase.
The factor is essential for the specific recognition of the promoter sequence on the DNA. It allows the RNA polymerase to bind tightly to the promoter and initiate transcription.
If the factor becomes non-functional, the RNA polymerase will not be able to recognize or bind to the promoter region, thereby preventing the initiation of transcription.
Answer: Binding of RNA polymerase to the promoter