The one gene-one enzyme hypothesis was postulated by

In the $lac$ operon system,the $lac$ gene-$I$ codes for:

Which enzyme is the expression product of the $y$ gene in the $lac$-operon?

Select two correct statements from the four $(a-d)$ given below regarding the $lac$ operon.
$(A)$ Glucose or galactose may bind with the repressor gene and induce inactivity.
$(B)$ In the absence of lactose,the repressor binds with the operator region.
$(C)$ The $z$-gene codes for permease.
$(D)$ This was elucidated by Francois Jacob and Jacques Monod.
Which of the following are the correct statements?

All of the following are part of an operon except:

In $lac$ operon,the gene '$i$' codes for repressor protein,the letter '$i$' indicates . . . . . . .