Question

in the porifera, water flows back out of the body through an opening called the ______.
a spicules
b sessile
c osculum
d none of the above

Explanation:

Porifera (sponges) have a specialized opening for water exit. Spicules are structural support structures, "sessile" describes their non-moving lifestyle, while the osculum is the large opening through which water exits the sponge body after passing through its internal canals.

Answer:

c. Osculum