What is semiconservative replication in the context of DNA replication?

• A. Each new DNA molecule consists of two newly synthesized strands.
• B. The original DNA molecule is completely broken down and new strands are synthesized from scratch.
• C. Both strands of the original DNA molecule are completely conserved in one of the new DNA molecules.
• D. Each of the two new DNA molecules contains one original strand and one new strand.

Answer: (D)

Verified step by step guidance

1. Understand the concept of DNA replication: DNA replication is the process by which a DNA molecule makes a copy of itself. This is crucial for cell division, allowing each new cell to have a complete set of DNA.
2. Learn about the semiconservative model: In semiconservative replication, each of the two new DNA molecules consists of one original (parental) strand and one newly synthesized strand. This model was proposed by Watson and Crick and later confirmed by the Meselson-Stahl experiment.
3. Differentiate from other models: The conservative model suggests that the original DNA molecule is completely conserved, and a new molecule is synthesized from scratch. The dispersive model suggests that each strand of both daughter DNA molecules contains a mixture of old and new DNA.
4. Visualize the process: During replication, the double helix unwinds, and each strand serves as a template for the formation of a new complementary strand. DNA polymerase is the enzyme that adds new nucleotides to form the new strand.
5. Recognize the significance: Semiconservative replication ensures genetic continuity between generations of cells, as each new cell receives one strand of DNA from the parent molecule, preserving the genetic information.