The $Lac-Operon$ model was elucidated by

Which of the following acts as an inducer for the $lac$ operon?

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

Repressor protein is formed from

Which of the following is required as an inducer for the expression of the $lac$ operon?

During $DNA$ transcription,$mRNA$ is usually single-stranded. However,sometimes an $RNA$ molecule is produced that is complementary to the $mRNA$. This is called ...... and its function is to ...... .