In $lac$ operon,$z$ gene codes for:

Select the $correct$ match:

In a negative operon,

$A$ gene that is responsible for the synthesis of a polypeptide chain is called a .......

$A$: Operator gene is functional when it is not blocked by repressor.
$R$: Regulator gene produces active protein only which acts on operon system in $E. coli$.

Select two statements out of the four given statements $(i-iv)$ with respect to the $lac$ operon.
$(i)$ Glucose or galactose binds with the repressor and inactivates it.
$(ii)$ In the absence of lactose,the repressor binds with the operator.
$(iii)$ The $Z$-gene codes for permease.
$(iv)$ It was elucidated by Francois Jacob and Jacques Monod.