During transcription, what is the role of RNA polymerase?

• A. It binds to DNA, reads the gene, and makes an RNA copy.
• B. It translates RNA into protein.
• C. It unwinds RNA.
• D. It repairs DNA.

Answer: (A)

RNA polymerase is the enzyme that carries out transcription. It binds to DNA at a promoter, opens the DNA strands to expose the gene, and uses one strand as a template to synthesize a complementary RNA molecule. The RNA is built in the 5' to 3' direction, creating an RNA copy of the gene that can later be processed into mRNA in eukaryotes or function directly in prokaryotes. This is separate from translation, where the RNA is used to build proteins at the ribosome, and from DNA repair, which is a different cellular process. So the best description is that RNA polymerase binds to DNA, reads the gene, and makes an RNA copy.