Why can glucose and galactose not act as inducers for the $lac$ operon?

Which of the following binds to the repressor,causing the repressor and the operator to dissociate from each other?

The functional complex that consists of a cluster of genes including structural genes,a promoter gene,an operator gene,and a regulator gene was discovered by:

Select the two correct statements out of the four $(i-iv)$ statements given below about the lac operon.
$(i)$ Glucose or galactose may bind with the repressor and inactivate it.
$(ii)$ In the absence of lactose,the repressor binds with the operator region.
$(iii)$ The $z$-gene codes for permease.
$(iv)$ This was elucidated by Francois Jacob and Jacques Monod.
The correct statements are:

When glucose is the normal energy source in a bacterial cell,which gene transcribes a repressor mRNA?

Which of the following statements is incorrect regarding the $lac$ operon?