Question

1 which of the following statements describes each new molecule of dna produced when dna replicates? a each new molecule is half the length of the original molecule. b each new molecule retains the a, c, and g bases in the dna sequence, but replaces the t base with u. c each new molecule has only the coding portions of the original molecule in its sequence. d each new molecule contains one strand from the original molecule and one newly synthesized strand.

Explanation:

DNA replication follows a semi-conservative model. Each original DNA double helix unwinds, and each strand serves as a template for synthesizing a new complementary strand. Thus, each new DNA molecule consists of one original (parental) strand and one newly made (daughter) strand. Option A is incorrect because new DNA molecules are the same length as the original. Option B is incorrect because U (uracil) is in RNA, not DNA. Option C is incorrect because DNA replication copies the entire sequence, not just coding portions.

Answer:

D. Each new molecule contains one strand from the original molecule and one newly synthesized strand.