What could cause the lac operon to shut off after it has been activated?

A. The binding of the sugar lactose to the promoter
B. The inactivation of RNA polymerase by the addition of a modified sugar
C. The binding of the repressor to the operator after all the lactose is degraded
D. The binding of the repressor to the promoter


Ans: C. The binding of the repressor to the operator after all the lactose is degraded

Biology & Microbiology

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The ?S and ?A alleles can be distinguished on the basis of __________

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