Transcription factors that act as activators have which effect on transcription?

• A. They bind to DNA to promote transcription
• B. They degrade mRNA
• C. They block RNA polymerase
• D. They are ribosomal proteins

Answer: (A)

Activators raise transcription by helping the RNA polymerase machinery access the gene. Transcription factors that act as activators bind to specific DNA sequences near a gene—such as promoter-proximal elements or enhancers—and recruit or stabilize components of the transcription machinery, often via coactivators. This makes it more likely that RNA polymerase II will bind the promoter and start transcribing, increasing the amount of mRNA produced.

The other options don’t fit this role: degrading mRNA would reduce transcript levels rather than promote initiation; blocking RNA polymerase would repress transcription; and ribosomal proteins are part of the ribosome and not transcription factors.