How does DNA replicate?

The Meselson-Stahl Experiment: DNA Replication Is Semiconservative
• Meselson and Stahl demonstrated that DNA replication is semiconservative because each strand of the original duplex becomes one of the two strands in each new duplex. (p. 288)

The Replication Process
• Replication of E. coli begins at a specific origin, proceeds bidirectionally, and ends at a specific terminus.
• Many enzymes function in DNA replication, including DNA primase, which creates a short RNA primer complementary to a DNA template; DNA helicase, which unwinds the helix in front of DNA polymerase, which then synthesizes new DNA by adding nucleotides to the growing strands; and DNA ligase, which creates phosphodiester bonds between adjacent Okazaki fragments.
• Replication can be divided into three stages: initiation, elongation, and termination.

Eukaryotic DNA Replication
• The major difference between prokaryotic and eukaryotic replication is that eukaryotic chromosomes have multiple replication origins, whereas prokaryotic chromosomes have a single point of origin.