Final answer:
An operon is a group of two or more genes under the transcriptional control of a single promoter. The promoter is a specific sequence of DNA nucleotides that binds transcription factors to control transcription initiation.
Step-by-step explanation:
An operon is a group of two or more genes under the transcriptional control of a single promoter.
The promoter is a specific sequence of DNA nucleotides that is located immediately upstream of the coding sequence. It binds transcription factors that control the initiation of transcription.
For example, the LAC operon in bacteria includes multiple genes responsible for lactose metabolism that are transcribed together under the control of a single promoter.