Final answer:
The lac repressor binds to the operator to prevent transcription by RNA polymerase; this is not achieved by DNA looping but by physical hindrance. Lactose binding to the repressor causes it to release from the operator, enabling transcription.
Step-by-step explanation:
The statement that DNA between the lac operon operators is looped out to sterically hinder RNA polymerase is false. In the absence of lactose, the lac repressor binds to the operator, which does physically prevent RNA polymerase from transcribing the operon's genes. However, when lactose is present, it binds to the repressor, causing a conformational change that results in the repressor dissociating from the operator.
This allows RNA polymerase to bind to the promoter and transcribe the genes necessary for lactose digestion. If there is a mutation in the operator that prevents the repressor from binding, RNA polymerase would be free to transcribe the genes even in the absence of lactose, potentially leading to unnecessary energy and resource expenditure by the cell.