The term Nucleic acid is derived from a greek word called Nuclein, coined by Miescher. Each molecule of Nucleic acid has basic units called Nucleotides and the most abundant Nucleic acid is RNA. There is roughly eight times more RNA than there is DNA, because, although DNA stores the much important bio-info, it is RNA which brings it into use. Picture it like this, although the brain is more important than the hands, we have only one brain, but two hands to carry out the work dictated by the brain.