| A | B |
|---|
| Phylum Porifera | sponges, means "pore-bearers"; sponges are classified as animals because they are multicellular, heterotrophic, have no cell walls, and contain a few specialized cells |
| sessile | sponges are sessile=they live entire life attached to a single spot |
| choanocyte | specialized cell in sponges that uses a flagellum to move a steady current of water through the sponge |
| osculum | a large hole at the top of the sponge through which water moves |
| spicule | spike-shaped structure that makes up the skeletons of harder sponges; made of either chalklike calcium carbonate or glasslike silica |
| archaeocyte | specialized cell in a sponge that makes spicules |
| intracellular digestion | digestion takes place within the cells |
| internal fertilization | process in which eggs are fertilized inside the female’s body |
| larva | immature stage of an organism that looks different from the adult form |
| gemmule | group of archaeocytes surrounded by a tough layer of spicules; produced by some sponges |
