Replication in E.coli DNA starts in a definite region known as

Options

A. Promoter region
B. Origin of replication
C. Replication fork
D. Template strand

Answer

To solve the question regarding where replication in E. coli DNA starts, we can break down the problem step by step:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the specific region in E. coli DNA where replication initiates.

2. **Reviewing the Options**:
- **Option 1: Promoter Region**: This is a sequence where RNA polymerase binds to initiate transcription, not replication.
- **Option 2: Origin of Replication**: This is the specific site on the DNA where replication begins. It is often referred to as "ori."
- **Option 3: Replication Fork**: This is the structure that forms during DNA replication as the DNA unwinds, but it is not the starting point of replication.
- **Option 4: Template Strand**: This refers to the strand of DNA that serves as a template for RNA synthesis during transcription, not the initiation of replication.

3. **Identifying the Correct Answer**: Based on the definitions and functions of each option, the correct answer is **Option 2: Origin of Replication**. This is the specific site on the E. coli DNA where the replication process begins.

4. **Explanation of the Correct Answer**: The origin of replication (oriC in E. coli) is a defined sequence of DNA where the replication machinery assembles and begins the process of DNA replication. It is crucial for ensuring that replication occurs accurately and efficiently.

### Final Answer:
The replication in E. coli DNA starts in a definite region known as the **Origin of Replication** (Option 2).

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