Which of the following is NOT a characteristic of stratified squamous epithelial tissue?

Stratified squamous epithelial tissue is defined by its multiple layers of cells, which serve various protective functions. This type of tissue is primarily found in areas subject to abrasion, such as the skin, esophagus, and oral cavity.

The characteristic of having a layered structure is fundamental to stratified squamous epithelium, as it consists of several layers of cells stacked upon each other. Keratinization refers to the formation of a tough, protective protein layer, commonly seen in the outer layers of the skin, which is also typical of stratified squamous epithelium, particularly in its keratinized form. The function of providing protection against mechanical and chemical stressors is a key role of this type of tissue, further supporting its abundance in high-friction areas.

In contrast, the claim of having a single layer of cells is inconsistent with the defining features of stratified squamous epithelial tissue. A single layer of epithelial cells describes simple epithelial tissue, not stratified. Therefore, the assertion that a single layer of cells is characteristic of stratified squamous epithelium is incorrect, confirming that this option is the one that does not belong.