One amongst the following is not the property of an ideal plasmid vector :

Options

A. It must contain ori site
B. It must have at least Evo selectable markers
C. It must have only one recognition site for at least one restriction endonuclease
D. The restriction site must be randomly placed in the entire plasmid

Answer

To determine which option is not a property of an ideal plasmid vector, we can analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understand the Properties of an Ideal Plasmid Vector:**
- An ideal plasmid vector should have certain essential features for effective cloning and replication in a host organism.

2. **Evaluate Option 1: ORI Site**
- The first option states that it must contain an ORI site (Origin of Replication). This is a fundamental property of plasmid vectors, as the ORI site is necessary for the plasmid to replicate within the host cell.
- **Conclusion**: This option is a property of an ideal plasmid vector.

3. **Evaluate Option 2: Selectable Markers**
- The second option states that it must have at least one selectable marker. Selectable markers are crucial for differentiating between recombinant and non-recombinant cells after transformation.
- **Conclusion**: This option is also a property of an ideal plasmid vector.

4. **Evaluate Option 3: Recognition Site for Restriction Endonuclease**
- The third option states that it must have only one recognition site for at least one restriction endonuclease. This is important because having a single recognition site allows for the precise insertion of foreign DNA without complications.
- **Conclusion**: This option is a property of an ideal plasmid vector.

5. **Evaluate Option 4: Random Placement of Restriction Sites**
- The fourth option states that a restriction site must be randomly placed in the entire plasmid. This is not a property of an ideal plasmid vector. Ideally, there should be a specific location for the restriction site to facilitate the insertion of foreign DNA without generating multiple fragments.
- **Conclusion**: This option is NOT a property of an ideal plasmid vector.

### Final Answer:
The option that is not a property of an ideal plasmid vector is: **"A restriction site must be randomly placed in the entire plasmid."**

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