DNA replication is considered semiconservative because after replication each daughter DNA molecule contains which of the following?

• A. Two newly synthesized strands and no parental (old) strands
• B. Two parental (old) strands and no newly synthesized strands
• C. One parental (old) strand and one newly synthesized strand
• D. A mixture of short interspersed segments of old and new DNA within each strand

Answer: (C)

Verified step by step guidance

1. Understand the concept of semiconservative DNA replication: during replication, the double-stranded DNA molecule separates into two single strands, each serving as a template for the synthesis of a new complementary strand.
2. Recall that in semiconservative replication, each daughter DNA molecule consists of one original (parental) strand and one newly synthesized strand, preserving half of the original molecule in each new DNA.
3. Contrast this with conservative replication, where the original double-stranded DNA remains intact and an entirely new double-stranded DNA molecule is synthesized, and dispersive replication, where old and new DNA segments are interspersed within each strand.
4. Recognize that the correct description of semiconservative replication is that each daughter DNA molecule contains one parental (old) strand and one newly synthesized strand.
5. Summarize that this mechanism ensures genetic continuity by conserving one original strand in each daughter molecule, which is why the answer is: one parental (old) strand and one newly synthesized strand.