25. Which of the following are non-keratinized? a) Interdental col b) Junctional epithelium c) Sulcular epithelium d) Parts of sulcular epithelium e) All of the above

The correct answer is e) All of the above.<br /><br />Non-keratinized epithelium is a type of epithelial tissue that does not have a layer of dead cells on its surface. It is found in areas of the body where there is a need for protection but not the presence of keratin, such as the lining of the mouth, esophagus, and vagina.<br /><br />In the context of the question, all the options listed (interdental col, junctional epithelium, sulcular epithelium, and parts of sulcular epithelium) are non-keratinized epithelium. These areas are found in the oral cavity and are lined with non-keratinized epithelium to provide protection and maintain the health of the teeth and gums.