Which statement is correct for homeotic genes?

In the $lac$ operon,which enzyme$(s)$ will be produced in the cell if there is a nonsense mutation in the $lac$ $y$ gene?

The $lac \, y$ gene codes for which of the following?

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?

Define an operon,give an example,and explain an inducible operon.

Which enzyme$(s)$ is/are responsible for the transformation of lactose to galactose and glucose in the $E. coli$ culture medium?