Which method of DNA replication involves new and old strands?

The semi-conservative method of DNA replication is characterized by each newly synthesized DNA molecule consisting of one original (old) strand and one newly created strand. This model was demonstrated in experiments by Meselson and Stahl, which showed that after one round of replication, the DNA consisted of equal parts of old and new material, confirming that each new double helix retained one of the original strands.

In semi-conservative replication, when the double helix unwinds, each strand serves as a template for the formation of a new complementary strand. This process ensures that genetic information is accurately maintained across generations of cells. The result is that following replication, each daughter DNA molecule has one parental strand and one newly synthesized strand, which is crucial for maintaining genetic fidelity.

The conservative method would suggest that the original double helix remains entirely intact while a completely new double helix is formed, which does not occur in biological systems. The dispersive model would imply that the parental DNA strands are broken into segments, and both strands of each new DNA molecule consist of segments from the old and new strands, which also does not accurately reflect the process observed in cells. Fragmentary replication is not a recognized model in the context of DNA replication. Thus, the semi-conservative method