The promoters of positively controlled operons require activator proteins because
A. RNA polymerase easily recognizes the consensus sequence.
B. they are required to inactivate the repressor proteins.
C. the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter.
D. they are needed to bind to the allosteric site of RNA polymerase.
Answer:C
The promoters of positively controlled operons require activator proteins because
A. RNA polymerase easily recognizes the consensus sequence. B. they are required to inactivate the repressor proteins. C. the promoters bind RNA polymerase weakly and utilize activator proteins to help RNA polymerase recognize the promoter. D. they are needed to bind to the allosteric site of RNA polymerase.