Complete the following sentences inserting appropriate words in blanks

a) Porifera are --------------- cellular animals incapable of ------------- as they remain ----------- to the substratum like a ----------------

b) The sponge body is covered by an outer epithelial layer made up of ------------------

c) Sponges with skeleton made up of spicules of calcium carbonate belong to the class -------- --------------

d) Hexactinellida are characterised by the presence of ---------------- spicules.

e) The flagellated chamber of the canal system of sponges is lined by ----------------------