Well the cell divides for a few reasons but for the most part it is a result of the cells growth in proportion to the cell membrane. What I mean by that is the cells internals so its organelles and just anything and everything grows at a faster rate than the cell membrane so to accommodate for the cells internals it must divide to accommodate the volume of the cell. That being said if a cell lacked a cell membrane wouldn't be protected by/from anything and the cell couldn't regulate the flow in and out of its self. so were is the correlation well if the volume of a object is increasing at a faster rate the perimeter of that given object the object would burst just how a virus spreads and kills cells our how a metal can of gas would be destroyed if ignited then sealed.
