the usual method of DNA replication is

Options

A. Conservative
B. Dispersive
C. Non-conservative
D. Semi-conservative

Answer

### Step-by-Step Solution:

1. **Understanding DNA Replication**:
- DNA replication is the biological process by which a cell makes an identical copy of its DNA. This is crucial for cell division and the transmission of genetic information.

2. **Structure of DNA**:
- DNA is composed of two strands that form a double helix. Each strand consists of a sequence of nucleotides.

3. **Template Mechanism**:
- During replication, each strand of the original DNA molecule serves as a template for the synthesis of a new complementary strand. This means that the existing strands guide the formation of new strands.

4. **Semi-Conservative Replication**:
- The method of DNA replication is described as semi-conservative. This means that after replication, each new DNA molecule consists of one original (template) strand and one newly synthesized strand.

5. **Outcome of Replication**:
- After one round of replication, each new DNA molecule is a hybrid, containing one old strand (from the original DNA) and one new strand (that has just been synthesized). This process continues in subsequent rounds of replication.

6. **Conclusion**:
- Therefore, the usual method of DNA replication is termed semi-conservative replication.

### Final Answer:
The usual method of DNA replication is semi-conservative.

---