Why is DNA replication described as semi-conservative?

• A. DNA replication requires the complete unwinding of the DNA helix.
• B. DNA replication occurs only in one direction along the DNA strand.
• C. DNA replication results in two completely new DNA molecules.
• D. Each new DNA molecule consists of 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 cell duplicates its DNA before cell division.
2. Learn about the semi-conservative model: In semi-conservative replication, each of the two new DNA molecules consists of one strand from the original DNA molecule and one newly synthesized strand.
3. Visualize the process: Imagine the original DNA double helix unwinding, with each strand serving as a template for the synthesis of a new complementary strand.
4. Recognize the significance: This model ensures genetic consistency, as each new DNA molecule retains one strand from the parent DNA, preserving the genetic information.
5. Compare with other models: Understand that alternative models, such as conservative or dispersive replication, do not accurately describe the observed mechanism of DNA replication.