Which term describes an epithelium with a single layer of cells?

• A. Pseudostratified
• B. Simple
• C. Stratified
• D. Transitional

Answer: (B)

Single-layer epithelium is described as simple epithelium. In this arrangement, all cells touch the basement membrane and form one cell-thick layer to the surface, which supports functions like diffusion, absorption, or secretion depending on the tissue location. The other terms describe different patterns: pseudostratified looks multi-layered because nuclei lie at different heights, but every cell still reaches the basement membrane; stratified epithelium has more than one cell layer stacked for greater protection; transitional epithelium can appear to change layers and shape as the tissue stretches, such as in the urinary bladder. So the term that best fits an epithelium with a single layer of cells is simple.