DNA replication is called semiconservative because
A) one of the two resulting DNA molecules is new.
B) the two resulting DNA molecules each have one new DNA strand and one old strand from the original DNA molecule.
C) both of the resulting DNA molecules are composed of new strands of nucleotides.
D) no extra nucleotides are incorporated into the replicated DNA molecules.
E) the sequence of nucleotides in one strand is conserved, whereas the new DNA molecule consists of a unique sequence of nucleotides

Question

Quizplus · Accepted Answer

Semiconservative replication means that each of the resulting DNA molecules has one original (old) strand and one newly synthesized strand. This has been experimentally demonstrated by the famous Meselson-Stahl experiment in 1958. Therefore, option B is the correct answer. Option A is incorrect because both strands of the resulting DNA molecules are new, and option C is incorrect because both strands are not new. Option D is incorrect because nucleotides are incorporated into the replicated DNA molecules, and option E is incorrect because both strands have the same sequence of nucleotides as the original DNA molecule.

DNA Replication Is Called Semiconservative Because