Function of 'ori' site in a vector is to

Options

A. Initiate insertional inactivation
B. Initiate replication
C. Codes for the proteins involved in replication of the plasmid
D. Initiate antibiotic resistance

Answer

### Step-by-Step Solution:

1. **Understanding the 'ori' Site**: The 'ori' site stands for the origin of replication. It is a specific sequence in the DNA where the replication process begins.

2. **Role in DNA Replication**: The 'ori' site serves as the starting point for DNA replication. At this site, various molecules and enzymes, including DNA polymerases, assemble to initiate the replication process.

3. **Importance in Vectors**: In the context of a vector (a DNA molecule used to deliver genetic material into a cell), the 'ori' site is crucial. Without it, the vector cannot replicate itself within the host cell.

4. **Transgene Replication**: If a vector contains a transgene (a gene that has been transferred from one organism to another), the presence of the 'ori' site allows for the replication of both the vector and the transgene. This means that every time the vector replicates, it also produces multiple copies of the transgene.

5. **Conclusion**: Therefore, the function of the 'ori' site in a vector is to initiate the replication process, ensuring that the vector and any inserted genes can be copied multiple times within a host cell.

### Final Answer:
The function of the 'ori' site in a vector is to initiate the replication process.

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