What does it mean when DNA replication is described as semiconservative?

• A. Each daughter DNA molecule contains one original (parental) strand and one newly synthesized strand.
• B. Each daughter DNA molecule contains two original (parental) strands, and the new strands remain separate.
• C. The parental DNA remains intact, and an entirely new double-stranded DNA molecule is produced without using the parental strands as templates.
• D. Each daughter DNA molecule contains two newly synthesized strands and none of the original strands.

Answer: (A)

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. Recall the structure of DNA: DNA is double-stranded, with two complementary strands running in opposite directions, held together by base pairing.
3. Define semiconservative replication: In semiconservative replication, each of the two new DNA molecules consists of one original (parental) strand and one newly synthesized strand.
4. Contrast semiconservative replication with other models: The conservative model suggests the original DNA remains intact and a completely new molecule is made, while the dispersive model suggests both strands are mixtures of old and new DNA.
5. Conclude that semiconservative replication means each daughter DNA molecule retains one parental strand paired with one new strand, preserving half of the original DNA in each molecule.