Question

Which of the following is a transcription factor produced by a regulatory gene?

• A. A promoter
• B. An operon
• C. A cofactor
• D. A repressor

Answer 1

The correct option is D A repressor

• A regulatory gene is a gene that controls the expression of one or more genes. The regulatory protein produced by the regulatory gene is called a repressor molecule. It binds to the operator or silencer region of the operon and controls the expression of structural genes by inhibiting its transcription.
• A promoter is the sequence of DNA that initiates transcription of a particular gene.
• An operon is a region of DNA that contains a cluster of genes that are under the control of a single promoter.
• A cofactor is a non-protein molecule that binds to the inactive enzyme (apoenzyme) and makes it active enzyme (holoenzyme).

Thus, the correct answer is 'A repressor.'