Which sequence correctly traces the steps of DNA replication during the S phase?
(1)Weak bonds between nitrogenous bases of the DNA are broken.
(2)DNA strands unwind.
(3)DNA polymerase binds to exposed nitrogenous bases.
(4)Ligases link together short complementary chains of nucleotides.
(5)Nitrogenous bases of the DNA strand attach to complementary nucleotides.
A) 1, 2, 3, 4, 5
B) 1, 2, 3, 5, 4
C) 5, 4, 3, 2, 1
D) 1, 3, 5, 2, 4
E) 4, 2, 3, 1, 5

Question

Quizplus · Accepted Answer

The first step of DNA replication is the breaking of weak hydrogen bonds between nitrogenous bases in the DNA strand, making the strands unwind (1, 2). Then, DNA polymerase binds to the exposed nitrogenous bases and begins adding complementary nucleotides to the template strand, creating a new complementary strand (3, 5). Finally, ligases come into the picture, linking together any short complementary chains of nucleotides that have been created, leading to the formation of the complete double-stranded DNA molecule (4). Hence, the correct sequence for DNA replication during the S phase is 1, 2, 3, 5, 4, which is depicted in choice B.

Which Sequence Correctly Traces the Steps of DNA Replication During