It is the expression of y gene in lac-operon

Define an operon, giving an example, explain an Inducible operon.

$A$ : 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

The regulatory genes are located

In the lactose operon of Escherichia coli, what is the function of promoter

$A$ : Lac operon exerts negative control only.
$R$ : The operator is occupied by aporepressor during regulation