Which type of epithelial tissue consists of a single layer of cells?

The type of epithelial tissue that consists of a single layer of cells is simple epithelium. Simple epithelium is characterized by its single layer formation, which allows it to be specialized for various functions such as absorption, secretion, and filtration. The single layer structure enables efficient exchange of materials, which is crucial in tissues lining internal organs and body cavities.

In contrast, stratified epithelium comprises multiple layers of cells, providing a protective barrier in areas subjected to abrasion, such as the skin. Columnar epithelium refers specifically to the shape and arrangement of the cells, which can be either simple or stratified; therefore, it does not inherently indicate the number of layers. Skeletal epithelium does not exist in the classification of epithelial tissue, as the term skeletal typically refers to muscle tissue rather than epithelial tissue.