In living organism during replication of DNA , the process is initiated by

Options

A. RNA primer
B. DNA primer
C. RNA & DNA primers
D. None of them

Answer

**Step-by-Step Solution:**

1. **Understanding DNA Replication**: DNA replication is the process by which a cell duplicates its DNA, resulting in two identical copies of the DNA molecule. This is crucial for cell division.

2. **Activation of Deoxyribonucleotides**: The first step in DNA replication involves the activation of deoxyribonucleotides, which are the building blocks of DNA.

3. **Unwinding of the DNA Strand**: The double-stranded DNA must unwind to allow access to the individual strands. This unwinding is facilitated by enzymes such as DNA gyrase and helicase.

4. **Addition of RNA Primer**: Before the actual synthesis of new DNA strands can begin, a short segment of RNA, known as the RNA primer, is synthesized. This primer is essential because DNA polymerases, the enzymes that synthesize new DNA, cannot initiate synthesis without a primer.

5. **Role of RNA Primer in Initiation**: The RNA primer is synthesized at the 5' end of the new DNA strand. It provides a starting point for DNA polymerase to begin adding DNA nucleotides. Thus, the RNA primer is critical for initiating the replication process.

6. **Removal of RNA Primer**: After the DNA synthesis has begun, the RNA primer is eventually removed, and the gaps are filled in with DNA nucleotides.

7. **Conclusion**: The initiation of DNA replication is primarily done by the RNA primer, making it the key component that starts the replication process.

**Final Answer**: The process of DNA replication is initiated by the RNA primer.

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