Where is a promoter located and what is its function in transcription?

• A. The enzyme that unwinds DNA during replication.
• B. The RNA sequence that codes for amino acids.
• C. A promoter DNA sequence at the start of a gene that binds RNA polymerase.
• D. The RNA that forms ribosomes.

Answer: (C)

In transcription, the promoter is a DNA sequence located upstream (at the start) of a gene. Its job is to recruit RNA polymerase (and, in eukaryotes, transcription factors) to the gene, establishing the direction and start point of transcription. It does not code for RNA or participate in DNA unwinding; those roles belong to other elements. The promoter’s function is to attract the transcriptional machinery so RNA polymerase can begin making RNA from the gene.