In a transcription unit promoter is said to be located towards :-

Options

A. 5 ' end of the structural gene
B. 3' end of the structural gene
C. 5' end of the structural gene
D. 3' end of the coding gene

Answer

To answer the question regarding the location of the promoter in a transcription unit, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding Transcription**:
- Transcription is the process by which messenger RNA (mRNA) is synthesized from a DNA template. This process is crucial for gene expression.

2. **Components of a Transcription Unit**:
- A transcription unit consists of three main components:
- **Promoter**: The region where RNA polymerase binds to initiate transcription.
- **Structural Gene**: The gene that is transcribed into mRNA.
- **Terminator**: The sequence that signals the end of transcription.

3. **Location of the Promoter**:
- The promoter is located upstream of the structural gene. Specifically, it is positioned at the 5' end of the structural gene. This means that it is found before the coding sequence that will be transcribed into mRNA.

4. **Conclusion**:
- Therefore, the correct answer to the question is that the promoter is located towards the **5' end of the structural gene**.

### Final Answer:
The promoter is said to be located towards the **5' end of the structural gene**.

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