There has been always a dispute among biologists in tracing the possible origin of cells. Did early cells arise from a single first cell or did numerous first cells originate independently. It is believed that nucleic acid evolved at first within the cell and then escaped away from the cell into the open ocean. The nucleic acids in each cell again condensed into thread like filaments involving protein as integral part of it, thus formed chromosomes. Furthermore a membrane came to be present around all the chromosomes in a cell leading to the evolution of nucleus, thus evolved multicellular organism.