Why is DNA replication described as semiconservative?

• A. Each daughter DNA molecule contains one original (parental) strand and one newly synthesized strand.
• B. Only one strand of the parental DNA is copied, while the other strand is degraded and not inherited.
• C. Both parental strands remain together in one daughter molecule while the other daughter molecule is composed entirely of new DNA.
• D. The parental DNA is broken into fragments, and each fragment serves as a template to make a completely new double helix.

Answer: (A)

Verified step by step guidance

1. Understand the structure of DNA: DNA is composed of two complementary strands forming a double helix.
2. Recall the process of DNA replication: during replication, the two strands of the parental DNA separate and each serves as a template for the synthesis of a new complementary strand.
3. Define semiconservative replication: this means that each new DNA molecule consists of one original (parental) strand and one newly synthesized strand.
4. Contrast semiconservative replication with other models: conservative replication would keep both parental strands together, and dispersive replication would mix fragments of old and new DNA in each strand.
5. Conclude that the semiconservative model explains how genetic information is accurately passed on, preserving one original strand in each daughter DNA molecule.