A student is revising Animal Diversity-I: a sponge body wall has many tiny pores through which water first enters. What should the student write in the answer sheet?

Ostia are small incurrent pores in the sponge body wall. They allow water to enter the canal system, carrying oxygen and food particles to internal cells. This MCQ belongs to the Porifera topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.