ABSTRACT
Within the past few years, the field of molecular biology has emerged as a powerful tool in medical and clinical research and also opened many exciting possibilities for the understanding, treatment, and imaging of a variety of diseases. Since the discovery of deoxyribonucleic acid (DNA) structure half a century ago, enormous advances in this field have been made. In 1865, Gregor Mendel, an Austrian monk, was the first to publish a theory about genetic rules that govern inheritance. By conducting crossbreeding experiments on pea plants, he was able to propose a generalized set of rules, known under the name of Mendel’s law of heredity or Mendelian inheritance. DNA is a long polymer of simple structural units called nucleotides with a backbone made of sugars and phosphate groups joined by ester bonds. Attached to the sugar is one of the four types of molecules called bases. The four bases present in DNA are classified into two differents subtypes: purine and pyrimidine.
