An organism that has more than one cell is called a pluricellular eukaryotic (pronounced yoo-kar-e-o-tic) organism. All organisms are eukaryotic except for bacteria, archea and virus. Bacteria have only one cell and are called prokaryotic cells. The difference between the to forms of cells is that eukaryotic cells have more organelles, ex: mitochondria, the endoplasmic rediculum, the gogli complex, chloroplast (plants only), ect. Eukaryotic cells have a cell membrane for protection, much like a prokaryotic cell does. Prokaryotic cells have a cell nucleus to hold DNA, but doesn't have a membrane to protect the DNA in the center of the cell, unlike a eukaryotic cell.