In the context of semiconservative replication, what does it mean for DNA replication to be semiconservative?

• A. Each daughter DNA molecule contains two newly synthesized strands and none of the original strands.
• B. Each daughter DNA molecule is a patchwork of old and new DNA segments within both strands.
• C. The parental double helix remains intact and a completely new double helix is synthesized separately.
• D. Each daughter DNA molecule contains one original (parental) strand and one newly synthesized strand.

Answer: (D)

Verified step by step guidance

1. Understand the concept of DNA replication: DNA replication is the process by which a cell copies its DNA before cell division, ensuring each daughter cell receives a complete set of genetic information.
2. Define semiconservative replication: In semiconservative replication, each of the two resulting DNA molecules consists of one original (parental) strand and one newly synthesized strand.
3. Contrast semiconservative replication with other models: For example, conservative replication would produce one molecule with both original strands and one with both new strands, while dispersive replication would produce strands that are mixtures of old and new DNA segments.
4. Recognize that the semiconservative model was experimentally supported by the Meselson-Stahl experiment, which showed that after replication, DNA molecules contain one old and one new strand.
5. Summarize that semiconservative replication ensures genetic continuity by preserving one original strand in each daughter DNA molecule, paired with a newly synthesized complementary strand.