Why is DNA replication described as semiconservative?

• A. Because the parental DNA is broken into fragments and each fragment is copied randomly.
• B. Because each new DNA molecule consists of one original (parental) strand and one newly synthesized strand.
• C. Because new DNA molecules are synthesized without using the original DNA as a template.
• D. Because both strands of the original DNA molecule are completely conserved in one of the daughter molecules.

Answer: (B)

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 that each daughter cell receives an identical set of genetic information.
2. Recall the structure of DNA: DNA is composed of two complementary strands twisted into a double helix, with each strand serving as a template for the synthesis of a new complementary strand.
3. Define semiconservative replication: In semiconservative replication, each of the two new DNA molecules contains one original (parental) strand and one newly synthesized strand.
4. Contrast semiconservative replication with other models: For example, conservative replication would keep the original double helix intact and produce a completely new double helix, while dispersive replication would produce strands with interspersed segments of old and new DNA.
5. Conclude why the correct answer is that each new DNA molecule consists of one original strand and one newly synthesized strand, which is the hallmark of semiconservative replication.