During DNA replication, the statement that each new double helix contains one old strand and one new strand describes which mode?

During DNA replication, the statement that each new double helix contains one old strand and one new strand describes which mode?

• A. Conservative replication
• B. Dispersive replication
• C. Semi-conservative replication
• D. Lytic replication

Answer: (C)

Semi-conservative replication describes how, after DNA copies, each new double helix has one old strand and one newly synthesized strand. The two strands unwind, and each old strand serves as a template for a new complementary strand, producing two daughter molecules that retain one parental strand each. This preserves genetic information through base pairing and explains how the original DNA is split between the two new molecules. It contrasts with conservative replication, where the original double helix remains together and a wholly new double helix is produced, and with dispersive replication, where parental and new DNA segments are mixed within the strands. The concept was supported by the Meselson–Stahl experiment, which showed that daughter molecules carried one old and one new strand.

Semi-conservative replication describes how, after DNA copies, each new double helix has one old strand and one newly synthesized strand. The two strands unwind, and each old strand serves as a template for a new complementary strand, producing two daughter molecules that retain one parental strand each. This preserves genetic information through base pairing and explains how the original DNA is split between the two new molecules. It contrasts with conservative replication, where the original double helix remains together and a wholly new double helix is produced, and with dispersive replication, where parental and new DNA segments are mixed within the strands. The concept was supported by the Meselson–Stahl experiment, which showed that daughter molecules carried one old and one new strand.