DNA polymerase is an enzyme that attaches matching nucleotides to the DNA strand in a process of replication.

DNA molecule in prokaryotes is usually single and circular, while eukaryotes have up to one thousand more genetic material in their nuclei. Replication process begins in one spot in prokaryotes, while a number of spots can be even several hundred in the DNA of eukaryotes. In both cases, replication is done in two directions.

In an experiment, a scientist has labeled nucleotides of the DNA molecule with radioactive elements, after which this molecule entered the replication process using non-radioactive nucleotides in making new strands. Since replication is done from one or more starting points in both directions, we can conclude that DNA molecules in both of the daughter cells will consist out of one strand from the DNA of the parental cell, which contains radioactive nitrogen, and the other strand that is made out of non-radioactive nucleotides.

DNA molecule in prokaryotes is usually single and circular, while eukaryotes have up to one thousand more genetic material in their nuclei. Replication process begins in one spot in prokaryotes, while a number of spots can be even several hundred in the DNA of eukaryotes. In both cases, replication is done in two directions. In eukaryotic cells, DNA molecule is wrapped around histones and forms nucleosomes. These structures slow down DNA polymerase, which moves about 50 times slower than in prokaryotes.

A DNA model can relate to a zipper in a way that the strands of the DNA are joined by hydrogen bonds in between nucleotides.

During replication, the coiling of the strands is undone just like how a zipper is when it is opened. The DNA strands open and separate like how a zipper opens and separates resulting in a new strand.

A zipper, when opened and closed may result to damages in the zipper. This is the same during DNA replication that leads to several mutations.