a bacterial operon is the region on the dna that includes genes cotranscribed into the same mRNa plus all of the adjacent cis-acting sequences required for transcription of these genes, including the genes' promoter as well as operators and other sequences involved in regulating the transcription of the genes. Because the genes of an operon are all transcribed from the same promoter and use the same regulatory sequences, all the genes of an operon can be transcriptionally regulated simultaneously• A bacterial operon is the region on the DNA that includes genes cotranscribed into the same mRNA plus all of the adjacent cis-acting sequences required for transcription of these genes, including the genes' promoter as well as operators and other sequences involved in regulating the transcription of the genes. Because the genes of an operon are all transcribed from the same promoter and use the same regulatory sequences, all the genes of an operon can be transcriptionally regulated simultaneously