BSC 2011 Study Guide
Chapter 33
Chapter 33 – An Introduction to Invertebrates
1. What is an invertebrate? Invertebrates account for what percentage of known animal species?
2. Characterize the sponges (Phylum Porifera). What are choanocytes?
3. Characterize the cnidarians (Phylum Cnidaria). Distinguish between a polyp and medusa.
Describe the stinging cells of cnidarians and how they work. Describe a generalized life cycle
of a cnidarian. Distinguish between the scyphozoans, cubozoans, hydrozoans, and anthozoans.
4. Characterize the flatworms (Phylum Platyhelminthes). Distinguish between the free-living
planarians, the parasitic trematodes, and the parasitic tapeworms. Describe the generalized
life cycle of a blood fluke.
5. Characterize the rotifers (Phylum Rotifera). What is parthenogenesis?
6. Characterize the ectoprocts (the bryozoans).
7. Characterize the brachiopods.
8. Characterize the molluscs (Phylum Mollusca). Distinguish between the chitons, gastropods,
bivalves, and cephalopods. What is a radula and its functions?
9. Characterize the annelid worms (Phylum Annelida). Distinguish between polychaete and
oligochaete worms. Distinguish between errantians, sedentarians, and leeches.
10. Characterize the nematode worms (Phylum Nematoda). What is ecdysis?
11. Characterize the arthropods. Distinguish between the chelicerates, myriapods, crustaceans,
and the insects. Distinguish and relate to examples of the winged insect orders and the
Zygentoma. Distinguish between incomplete metamorphosis and complete metamorphosis.
12. Characterize the echinoderms (Phylum Echinodermata). Distinguish between the Ateroidea,
Ophiuroidea, Echinoidea, Crinoidea, and Holothuroidea. How does the water vascular
system function?
13. For each group mentioned above, be able to recognize and relate to examples of
species (by common name) as covered within the text.
14. How do organisms maximize surface area?
Key Terms – filter feeders, spongocoel, osculum, choanocytes, mesohyl, amoebocytes,
hermaphrodites, gastrovascular cavity, polyp, medusa, cnidocyte, nematocyst, exoskeleton,
planula, polymorphism, protonephridia, flame bulbs, planarians, parthenogenesis, lophopohore,
trocophore larva, foot, visceral mass, mantle, mantle cavity, radula, ammonites, polychaete,
oligochaete, hirudin, metanephridia, cuticle, molting, trichinosis, open circulatory system,
chelicerae, eurypterids, arachnids, pedipalps, isopods, decapods, copepods, krill, barnacles,
Hexapoda, Malpighian tubules, tracheal tubes, cerebral ganglion, incomplete metamorphosis,
complete metamorphosis, Coleoptera, Diptera, Hymenoptera, Lepidoptera, Hemiptera,
Orthoptera, water vascular system, madreporite, ampullae
Note: This study guide may not be all inclusive of material covered. The student is responsible for learning all
material covered in lecture and as expected as part of this course.