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.
The principle structural types are simple and stratified. Simple epithelium has only one layer of cells, while stratified epithelium has two or more layers. The form and function classifications of epithelial tissue are cuboidal, squamous, and columnar. rare type of this tissue, stratified columnar epithelium, is only found in a few places in the body, including parts of the anus, conjunctiva in the eye, uterus, and pharynx. Epithelial tissue is classified in two ways: based on structure, and based on form and function.