A student is revising Animal Diversity-I: the thin outer covering of a sponge is formed by flattened cells. What should the student write in the answer sheet?

Pinacocytes are flattened cells forming the outer surface, or pinacoderm, of sponges. They help protect and maintain the body shape but do not form a true tissue in the strict sense. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.