DNA is a double-stranded, helical molecule composed of nucleotides, each of which contains a phosphate group, a sugar molecule, and a nitrogenous base. Because there are four naturally occurring ...

Double-stranded DNA consists of two polynucleotides that are arranged such that the nitrogenous bases within one polynucleotide ... C, and G nucleotides within an organism's DNA is unique to ...

Each strand can be used as a template to create a new DNA molecule. Free DNA nucleotides – needed to form the new strands. DNA polymerase – an enzyme that adds new nucleotides to a growing str ...