1. Sponges 26-2

2. Choanocyte Specialized cell in sponges that uses a flagellum to move a steady current of water through the sponge.

3. Osculum Large hole at the top of the sponge through which water leaves the sponge.

4. Spicule Spike-shaped structure that makes up the skeletons of harder sponges; made of either calcium carbonate or silica.

5. Archaeocyte Specialized cell in a sponge that makes spicules.

6. Internal Fertilization Process in which eggs are fertilized inside the female’s body.

7. Larva Immature stage of an organism that looks different from the adult form.

8. Gemmule Group of archaeocytes surrounded by a tough layer of spicules; produced by some sponges.

9. Hmmm…. Why are sponges classified as animals?

10. Sponges are classified as animals because they are multicellular, heterotrophic, have no cell walls, and contain a few specialized cells.

11. Well…. How do sponges carry out essential functions?

12. The movement of water through the sponge provides a simple mechanism for feeding, respiration, circulation, and excretion.