At the chemical level, the DNA of prokaryotic cells, which have no nuclear membranes, and that of eukaryotic cells, which have separate, membrane-enclosed nuclei, is identical. DNA is a long, double-stranded molecule containing a backbone of repeating, alternating sugar and phosphate units.
Simple cuboidal epithelium is a type of epithelial tissue found in the body. It is a single layer thick and made of cube-shaped cells. This type of tissue is found lining parts of the body such as the kidney tubules and walls of respiratory bronchioles.
Simple Squamous Epithelium A simple squamous epithelium consists of a single layer of flat epithelial cells resting on a basement membrane. The peripheral cytoplasm of each squamous epithelial cell is very thin, so thin that it is only resolvable at approximately 1000X magnification or better.