Synthesis of recombinant DNA requires :

Options

A. enzymes
B. Vehicle DNA
C. passenger DNA
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Recombinant DNA**:
- Recombinant DNA is formed by joining DNA from two different species using recombinant DNA technology. This process allows for the manipulation and combination of genetic material.

2. **Identifying the Requirements**:
- The synthesis of recombinant DNA requires three main components:
- **Enzymes**: These are crucial for cutting and joining DNA molecules.
- **Vehicle DNA**: This refers to the vectors that carry the foreign DNA into the host cells.
- **Passenger DNA**: This is the DNA segment that is isolated from the desired organism and inserted into the vector.

3. **Role of Enzymes**:
- Restriction enzymes are used to cut DNA at specific sites, allowing for the insertion of foreign DNA. DNA ligase is then used to join the cut ends of the DNA together.

4. **Role of Vehicle DNA**:
- Vehicle DNA, or vectors, are DNA molecules that transport the passenger DNA into the recipient cells. They ensure that the foreign DNA can be replicated and expressed within the host organism.

5. **Role of Passenger DNA**:
- Passenger DNA is the specific piece of DNA that contains the gene for the desired traits. This DNA is inserted into the vector for cloning and further manipulation.

6. **Conclusion**:
- Since all three components (enzymes, vehicle DNA, and passenger DNA) are essential for the synthesis of recombinant DNA, the correct answer to the question is "all of these."

**Final Answer**: All of these.

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