Question

Which of the following is not a component of lac operon?

• A. Primer gene
• B. Promoter gene
• C. Structural gene
• D. Regulator gene

Answer 1

The correct option is A Primer gene

• Promotor gene, operator gene, structural genes and regulator gene are the genes present in the lac operon.
• The promoter gene is the region where RNA polymerase binds to begin the transcription of the structural genes.
• There are 3 structural genes in lac operon - lac Z, lac Y and lac A.
• Regulator gene is the gene that produces the lac repressor protein. In the absence of lactose, it binds to the operator and prevents the transcription of the structural genes.

So, the correct answer is 'primer gene'.