The structure that causes the synthesis of RNA to cease is the __________.

• A. Transcription terminator
• B. Promoter region
• C. Stop codon
• D. Anticodon

Answer: (A)

Transcription termination signals stop RNA synthesis. A transcription terminator is the DNA sequence that tells RNA polymerase to stop and release the RNA transcript. In bacteria, termination can occur intrinsically when the newly made RNA forms a GC-rich hairpin followed by a string of uracils, which destabilizes the transcription complex, or with the help of the Rho protein that catches up to the polymerase and prompts release. The promoter region is what starts transcription, not ends it; a stop codon terminates translation, not transcription; and an anticodon is part of tRNA involved in decoding mRNA during translation.