DNA

DNA stands for Deoxyribonucleic acid. DNA contains the genetic instructions used in the development and functioning of all known living organisms. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information. DNA is organized into structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. DNA is a long polymer made from repeating units called nucleotides. When a Base linked to a sugar is called a nucleoside. When a base linked to a sugar and to a phosphate group it is called as nucleotide.

Backbone of the DNA strand is made from alternating phosphate and sugar residues. The DNA double helix is stabilized by hydrogen bonds between the bases attached to the two strands. The four bases found in DNA are adenine, cytosine, guanine and thymine. Watson, Crick, and Wilkins jointly received the Nobel Prize for Discovering the structure of DNA molecule.