When a cell divides, each daughter cell must receive its full complement of genetic material in the form of chromosomes containing DNA, or deoxyribonucleic acid. A chromosome is made up of two long strands of DNA and several types of proteins . A DNA strand is composed of a long backbone of sugar and phosphate units . One of our different nucleotide bases -- A, T, C or G -- hang off each sugar unit. The sequence of the bases encodes genetic information. The three steps in the process of DNA replication are initiation, elongation and termination