An operon is [ Select ] ["a short sequence of DNA to which a transcription regulator binds", "a sequence of eukaryotic DNA that produces a variety of mRNA transcripts", "a set of genes transcribed as a single mRNA from a single promoter", "a set of genes controlled by the binding of two or more transcription regulators"] and the Trpoperon would be inactivate/ activated/unchange [ Select ] ["inactivated (turned off)", "activated (turned on)", "unchanged in presence of tryptophan since it is constitutively active"] when tryptophan is present. Eukaryotes can turn on multiple genes at once by using the same transcriptional regulator for different genes [ Select ] ["False", "True"] a short sequence of DNA to which a transcription regulator binds a sequence of eukaryotic DNA that produces a variety of mRNA transcripts a set of genes transcribed as a single mRNA from a single promoter a set of genes controlled by the binding of two or more transcription regulators.