BIOL 205 Lecture Notes - Lecture 2: Microvillus, Vacuole, Meiosis
Document Summary
Major subgroups: calcarea, refers to the fact that their spicules are made from calcium carbonate (caco3, 1-rayed, 3-rayed or 4-rayed, hexactinelida, 6-rayed, basically glass, made of silica (sio2, demospongiae, never 6-rayed. Will only be found in a calcarea sponge. Water can enter the sponge through a single sponge: porocytes (you will not see these in other body plans, porocytes is a single cell that creates a hole called the ostium. On the outside of the cell there are a bunch of flatter cells (known as pinnacocytes) If the(cid:455)"re outside of the spo(cid:374)ge, we refer to them as exopinnacocytes. If the(cid:455)"re i(cid:374)side of the spo(cid:374)ge, we refer to them as endopinnacocytes. The choanoderm consists of choanocytes, which line the inside of the sponge in the spongecoel/atrium. The mesohyl is a complex middle layer that consists of a jelly-like matrix, spicules, and living cells. You only see them in calcarea and hexactinelida sponges.
