The important of the Watson and Crick model lies in the fact that is attempts to explain its biological functions .three function  have been attributed to this molecule: (1) storage of hereditary information, (2) the ability to selfdupicate, and (3) the capacity to direct and control cell activities. The model suggests that the genetic information resides in a  linear sequence of bases and a DNA segment corresponds to a gene or a collection of genes. The critically of the model was that it provided a clue to self –duplication where each of the polynucleotide chains acts as a template to generate a new chain. The week hydrogen bonds are readily broken and reformed when duplication takes place.

          As for the third functions, DNA is the controller and guide of all kinds of cell activities, a clue for which was provided by mutational studies. A mistake in the information content of the molecule result in accumulation of errors at the transcriptional level.