Cells, like these prokaryotic E. coli cells, replicate themselves quickly and efficiently. Part of the process of asexual reproduction is the ability of cells to make identical copies of their of their DNA before cell division occurs. Prokaryotic cells that reproduce by binary fission rely on the fast, accurate process of DNA replication to ensure future generation of cells will have the same genetic instructions as the parent cell. The structure of DNA aids in the speed and accuracy of replication. Double stranded DNA is a polymer of two strands of nucleotides which are hydrogen bonded to each other to form a double helix. Nucleotides are molecules that consist of a deoxyribose sugar, a phosphate and one of four nitrogenous bases. The phosphodiester backbones consist of alterating sugar and phosphate groups. The nitrogenous bases include cytosine, thymine, adenine, and guanine. Cytosine forms three hydrogen bonds with guanine and thymine forms two hydrogen bonds with adenine. This is referred to as complementary base pairing, The double helix will have one strand oriented in a 5'-3' direction relative to the