Characteritics of vector include al, except

Options

A. Presence of 'ori'
B. Presence of antibiotic gene as selectable marker
C. Large size
D. MCS

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the characteristics of vectors and specifies that we need to identify which option does not belong to the characteristics of vectors.

2. **Analyzing the Options**:
- **Option 1: Presence of ORI (Origin of Replication)**: This is a characteristic of vectors. The ORI allows the vector to replicate independently within a host cell. Therefore, this option is not the correct answer.

- **Option 2: Presence of antibiotic gene as a selectable marker**: Vectors often contain antibiotic resistance genes that serve as selectable markers. These markers help in identifying cells that have successfully taken up the vector. Hence, this is also a characteristic of vectors and not the correct answer.

- **Option 3: Presence of large size**: Vectors are typically small in size, which allows them to be easily taken up by host cells. Therefore, this option is not a characteristic of vectors and is the correct answer to the question.

- **Option 4: Presence of MCS (Multiple Cloning Site)**: Vectors usually have multiple cloning sites that allow for the insertion of foreign DNA. This is an important characteristic of vectors, making this option not the correct answer.

3. **Conclusion**: The characteristic that does not belong to vectors is "presence of large size." Therefore, the answer is Option 3.

### Final Answer:
The characteristic of vectors that does not belong is the "presence of large size."

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