In the $lac$ operon,which molecule binds to the promoter site?

Statement-$I$: Lac operator is present only in lac operon and it interacts specifically with lac-repressor only.
Statement-$II$: Each operon has its specific operator and specific repressor.

Repressor protein is formed from

What does '$3$' represent in the given figure?

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

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.