In an overview of transcription, what is the primary role of RNA polymerase?

• A. It removes introns from a pre-mRNA transcript and ligates exons together.
• B. It adds amino acids to a growing polypeptide chain using an mRNA template at the ribosome.
• C. It joins Okazaki fragments to form a continuous DNA strand during DNA replication.
• D. It binds to a promoter, unwinds the DNA locally, and catalyzes synthesis of an RNA strand complementary to the DNA template.

Answer: (D)

Verified step by step guidance

1. Understand that transcription is the process by which RNA is synthesized from a DNA template.
2. Recognize that RNA polymerase is the enzyme responsible for this process.
3. Know that RNA polymerase binds specifically to a DNA sequence called the promoter to initiate transcription.
4. Realize that RNA polymerase unwinds the DNA locally to expose the template strand for RNA synthesis.
5. Acknowledge that RNA polymerase catalyzes the formation of an RNA strand by adding ribonucleotides complementary to the DNA template strand.