The trp operon is an example of a Blank 1 Question 13[select: , negative repressible, operator, blocks, enhances, promotor, negative inducible, positive repressible, positive inducible, activator] operon. This is because its regulatory region contains an Blank 2 Question 13[select: , negative repressible, operator, blocks, enhances, promotor, negative inducible, positive repressible, positive inducible, activator] , which suppresses transcription and because binding of tryptophan to the repressor protein Blank 3 Question 13[select: , negative repressible, operator, blocks, enhances, promotor, negative inducible, positive repressible, positive inducible, activator] transcription.多重下拉选择题