Sponges are comprised of several cell types, which are similar to those found in the eumetazoa, but also display a unique degree of flexibility. complete each sentence to correctly describe these cell types as they relate to the sponges.

sponges are

phylum Porifera

Explanation: There are about nine thousand species of sponges. Sponges have three types of cells which includes

1) Pinacocytes: They are thin walled and flat cells. They line the outer surface of a sponge. Pinacocytes are slightly contractile. The contraction may change the structure of some sponges. Most pinacocytes forms tube like contractile porocytes. Porocytes are responsible for water regulation.

2) Mesohyl: It is a jelly like layer present underneath the pinacocytes. Amoeboid cells are present in mesophyl. The Amoeboid cells are called mesenchyma cells. These cells are responsible for reproduction, secretion, skeletal elements, transporting and storing food and forming contractile rings around openings in the sponge wall.

3)Choanocytes: Also called collar cells are present below the mesohyl. They form the lining of the inner chamber. Choanocytes are flagellated cells. They have a collar like ring of microvilli surrounding a flagellum.The flagellum creates water currents through the sponge.

really dont know just need some points

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.