What is the general role of a transcription factor?

• A. It binds DNA and modulates transcription.
• B. It catalyzes RNA synthesis.
• C. It edits mRNA sequences.
• D. It degrades mRNA.

Answer: (A)

Transcription factors are regulatory proteins that control gene expression by recognizing and binding to specific DNA sequences near a gene. This binding helps recruit or block RNA polymerase II and other parts of the transcriptional machinery, and can recruit chromatin modifiers to open or compact the DNA, adjusting whether transcription occurs and at what level in response to cellular signals. They don’t catalyze RNA synthesis—that job belongs to RNA polymerase—nor do they edit or degrade mRNA; those are separate post-transcriptional processes. So the main role is to bind DNA and modulate transcription.