What signals RNA polymerase to release the newly made RNA and depart from the gene?

• A. Promoter
• B. Terminator sequence
• C. Enhancer
• D. Operator

Answer: (B)

Termination signals in the DNA, the terminator sequence, tell RNA polymerase where to stop and release the RNA transcript, causing the enzyme to detach from the DNA template. As the polymerase transcribes this region, it encounters a cue that leads to pausing and dissociation, freeing both the RNA and the polymerase. In bacteria, this can happen via rho-independent mechanisms—where a hairpin structure in the RNA followed by a string of uracils destabilizes the complex—or via rho-dependent mechanisms, where the rho protein helps dislodge the polymerase. The promoter is where transcription begins, the enhancer boosts how much transcription occurs, and the operator is a regulatory site for repressors; none of these directly signal termination.