The United Illuminating Company (UI) is a regional electric distribution company based in Orange, Connecticut.
Although generally not visible to the naked eye, organisms composed of prokaryotic cells still dominate the earth. Their collective mass is at least 10 times greater than the mass of all eukaryotes combined. Organisms composed of prokaryotic cells are classified into 2 main groups: archaea and bacteria. Archaea most closely resemble the first primitive cells on our planet.
Prokaryotic cells are simple, one-celled organisms; such as bacteria. All other life is composed of Eukaryotic cells. Not surprisingly, Prokaryotic cells are far simpler in structure and they are also much smaller than Eukaryotic cells. Eukaryotic cells are around 15 times wider and can be up to 1,000 times larger in volume. In addition to having a nucleus, Eukaryotic cells have a nucleolus containing the cell's DNA, as well as specific membrane-bound compartments, organelles, where specific metabolic activities occur. Prokaryotic cells do not have a nucleus or contain these more complex inner structures.