DNA replication is described as semiconservative. What does this mean about the composition of the daughter DNA molecules after replication?

• A. Each daughter DNA molecule contains two newly synthesized strands and none of the original strands.
• B. One daughter DNA molecule contains both parental strands, and the other contains both newly synthesized strands.
• C. Each daughter DNA molecule contains one parental (old) strand and one newly synthesized strand.
• D. Each daughter DNA molecule is a mixture of old and new DNA segments within each strand (interspersed patches).

Answer: (C)

Verified step by step guidance

1. Understand the concept of semiconservative DNA replication: it means that each new DNA molecule consists of one original (parental) strand and one newly synthesized strand.
2. Recall that 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. Recognize that the result is two daughter DNA molecules, each containing one strand from the original molecule and one newly made strand.
4. Contrast this with other models such as conservative replication (where one molecule has both original strands and the other has both new strands) and dispersive replication (where strands are mixtures of old and new segments).
5. Conclude that semiconservative replication ensures genetic continuity by preserving one original strand in each daughter DNA molecule.