The synthesis of identical copies of DNA is called replication (or) Duplication of DNA. DNA is duplicated so that the DNA in the New cell is identical to original DNA. Replication of DNA is enzyme catalysed process. In this 2-strands of DNA strats unconding at perticuler region.
Which of the following Biomolecules self repair mechanism.

Options

A. DNA, RNA & Protein
B. DNA & RNA
C. Only DNA
D. Only RNA

Explanation

To solve the question regarding which biomolecules have a self-repair mechanism, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding DNA Replication**:
- DNA replication is the process where identical copies of DNA are synthesized from the original DNA. This is crucial for cell division and ensuring that each new cell has the same genetic material as the parent cell.

2. **Identifying the Enzymes Involved**:
- The process of DNA replication is enzyme-catalyzed, primarily involving DNA-dependent DNA polymerases. These enzymes are responsible for synthesizing new DNA strands by adding nucleotides complementary to the template strand.

3. **Types of DNA Polymerases**:
- There are three main types of DNA polymerases involved in DNA replication:
- **DNA Polymerase I**: Involved in DNA repair and has a self-repair mechanism.
- **DNA Polymerase II**: Less active and primarily involved in DNA repair.
- **DNA Polymerase III**: The main enzyme responsible for DNA replication.

4. **Self-Repair Mechanism**:
- Among the enzymes mentioned, DNA Polymerase I is noted for its self-repair mechanism. This means it can correct errors that occur during DNA replication, ensuring the fidelity of the genetic material.

5. **Evaluating Other Biomolecules**:
- RNA and proteins do not possess a self-repair mechanism like DNA does. While RNA can be synthesized from DNA, it does not have the same capacity for self-correction or repair. Proteins also do not have a self-repair mechanism; they rely on cellular processes for degradation and synthesis.

6. **Conclusion**:
- Based on the above analysis, the biomolecule that has a self-repair mechanism is **DNA**. Therefore, the correct answer to the question is **DNA only**.

### Final Answer:
- The biomolecule with a self-repair mechanism is **DNA only**.