Final answer:
Keratinized cells contain keratin and are found in the skin, mouth, and nose, providing a tough barrier. Non-keratinized cells lack keratin and are found in mucosal surfaces, protecting them and maintaining a moist environment.
Step-by-step explanation:
Keratinized cells contain keratin, a cytoskeletal protein, and are found in the skin, mouth, and nose, providing a tough, impermeable barrier. Non-keratinized cells lack keratin and are found in the mucosal surfaces of the body, such as the mouth, esophagus, and vagina. They play a role in protecting these surfaces from pathogens and maintaining a moist environment.