The main role of DNA polymerase III is

Options

A. addition and polymerization of nucleotides from 5' end to 3' end.
B. as major repair enzyme form 5' and to 3' end.
C. removal of DNA primer from 5' end.
D. addition and polymerization of nucleotides from 3' end to 5' end.

Answer

To answer the question about the main role of DNA polymerase III, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding DNA Replication**:
- DNA replication is the process by which a DNA molecule makes a copy of itself. This is essential for cell division and the transmission of genetic information.

2. **Role of Enzymes in DNA Replication**:
- Various enzymes are involved in DNA replication, including helicase, which unwinds the DNA double helix, and primase, which synthesizes a short RNA primer.

3. **Introduction to DNA Polymerases**:
- There are several types of DNA polymerases, particularly in prokaryotes (like bacteria). The three main types are:
- DNA Polymerase I: Mainly involved in DNA repair.
- DNA Polymerase II: Also involved in DNA repair but to a lesser extent.
- DNA Polymerase III: The primary enzyme responsible for DNA synthesis.

4. **Function of DNA Polymerase III**:
- The main role of DNA Polymerase III is to add nucleotides to the growing DNA strand during replication. It synthesizes new DNA strands by adding nucleotides in the 5' to 3' direction.

5. **Evaluating the Options**:
- Based on the information:
- **Option A**: Addition and polymerization of nucleotides from 5' end to 3' end – This is correct and describes the main role of DNA Polymerase III.
- **Option B**: Major repair enzyme from 5' to 3' end – This is incorrect; that role belongs to DNA Polymerase I.
- **Option C**: Removal of DNA primer from 5' end – This is incorrect; this function is performed by other enzymes.
- **Option D**: Adhesion and polymerization of nucleotides from 3' end to 5' end – This is incorrect; DNA synthesis occurs from 5' to 3'.

6. **Conclusion**:
- Therefore, the main role of DNA Polymerase III is the addition and polymerization of nucleotides from the 5' end to the 3' end.

### Final Answer:
The main role of DNA polymerase III is the addition and polymerization of nucleotides from the 5' end to the 3' end.

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