In E.coli, complete DNA replication requires

Options

A. 38 minutes
B. 20 minutes
C. 19 minutes
D. 3 minutes

Answer

To solve the question regarding the time required for complete DNA replication in E. coli, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Generation Time**:
- Generation time is the time taken by a bacterial population to double in number. For E. coli, this time is crucial for understanding its replication process.

2. **Identify the Generation Time for E. coli**:
- Research indicates that E. coli has a generation time of approximately 20 minutes under optimal conditions. This means that E. coli can replicate its DNA and divide into two cells in about 20 minutes.

3. **Analyze the Given Options**:
- The options provided are:
- A) 38 minutes
- B) 20 minutes
- C) 19 minutes
- D) 3 minutes
- Since we know that the generation time for E. coli is 20 minutes, we can eliminate options A, C, and D as they do not match this known value.

4. **Select the Correct Answer**:
- The only option that matches the known generation time for E. coli is option B, which states 20 minutes. Thus, this is the correct answer.

### Final Answer:
- The complete DNA replication in E. coli requires **20 minutes** (Option B).