DNA
DNA is Deoxyribosenucleic acid. DNA is the hereditary material that is passed on from one generation to the next during reproduction. DNA directs and controls the development and activities of all the cells in an organism.

STRUCTURE OF DNA
The DNA molecule is a long chain of repeating units, called nucleotides. The base of DNA is composed of deoxyribose bonded to a phosphate group and a nitrogen base. The four nitrogenous bases are Adinine, Thymine, Cytocine, Guanine. Adinine always bonds to Thymine and Cytocine is always bonded to Guanine.