Ribonucleic acids (RNA) are a form of genetic material. There is much evidence, such as it's ability to self catalyse, to suggest that RNA was the first form of genetic material on earth, which is known as the RNA world hypothesis. However new evidence has come to light which suggests that RNA and DNA (Deoxyribonucleic Acid) appeared in a primitive form at the same time. RNA comes in many forms such as mRNA, tRNA and rRNA. It has a basic structure of the pentose sugar ribose, with a 5' phosphate group, a 2' and 3' hydroxyl group, and a 1' nucleic acid. The 2' hydroxyl group is one of the reasons for it's functional flexibility which makes it less stable molecule than DNA. Hence, it is not used as the main genetic molecule as it can be hydrolysed easily.