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

Who provided the clear explanation of the $Lac$ operon?

How many operons are present in the $nif$ gene cluster of $Klebsiella$ $pneumoniae$?

$A$ low level of expression of lac operon occurs at all the time. Can you explain the logic behind this phenomenon?

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:

Which of the following is not produced by $E. coli$ in the lactose operon?