The RNA polymerase holoenzyme transcribes

Options

A. the promoter, structural gene and the terminator region
B. the promoter, and the structural gene
C. the structural gene and the terminator regions
D. the structural gene only

Explanation

**Step-by-Step Solution:**

1. **Understanding RNA Polymerase Holoenzyme**: The RNA polymerase holoenzyme is a multi-subunit enzyme responsible for synthesizing RNA from a DNA template during the process of transcription. It consists of a core enzyme and a sigma factor that helps in recognizing the promoter region of the gene.

2. **Identifying the Function of RNA Polymerase**: The primary function of RNA polymerase is to transcribe DNA into RNA. This involves three main stages: initiation, elongation, and termination.

3. **Role of Promoter Genes**: The transcription process begins at the promoter region of the gene. The promoter is a specific sequence of DNA that signals the start of transcription. RNA polymerase binds to the promoter region to initiate transcription.

4. **Transcription Process**:
- **Initiation**: RNA polymerase binds to the promoter region, unwinds the DNA, and starts synthesizing RNA.
- **Elongation**: As RNA polymerase moves along the DNA template, it adds ribonucleotides to the growing RNA strand, complementary to the DNA template. This is where the structural genes come into play, as they are the actual sequences that are transcribed into RNA.
- **Termination**: The transcription process continues until RNA polymerase reaches a termination signal in the DNA. This signal instructs the polymerase to stop transcription and release the newly synthesized RNA molecule.

5. **Conclusion**: Therefore, the RNA polymerase holoenzyme transcribes the structural genes of the DNA, resulting in the synthesis of mRNA, which carries the genetic information necessary for protein synthesis.