Bio1151b Chapter 33 Invertebrates
  1. Invertebrates do not have a           , and account for 95% of known animal species.
  2. Phylum           are the multicellular sponges. A single       layer develops into specialized cells such as              ,            , and              .
  3. Phylum           belong in the clade with true          called            . This phylum is diploblastic and is divided into four major classes: Hydrozoa, Scyphozoa, Cubozoa, and Anthozoa.
  4. Most Eumetazoa belong to the clade            and exhibit            symmetry and triploblastic embryonic development.
  5. Phylum                  are flatworms with a gastrovascular cavity that lacks a         . The       classes are: Turbellaria, Monogenea, Trematoda, and Cestoidea.
  6. Phylum           are roundworms with a               and a tough coat called a          covering the body. Some nematodes are parasites of plants and animals; human parasites include Trichinella, Ascaris, and filarial nematodes.
  7. Phylum           are segmented worms with a true         . The        major classes are: Oligochaeta, Polychaeta, and Hirudinea.
  8. Phylum           are soft-bodied animals whose body consist of a muscular       , a visceral       , and a         . A ciliated larval stage called a              places this phylum in the clade                 . The       major classes are: Gastropoda, Bivalvia, Cephalopoda, and Polyplacophora.
  9. Phylum             have            bodies with          appendages and an              made of         . The exoskeleton requires them to       as they grow, placing them in the clade            . The       major subphyla are: Cheliceriformes, Myriapoda, Hexapoda, and Crustacea.
  10. Phylum                are                and possess a bumpy or spiny skin that covers an               , and a        vascular system. The      classes are: Asteroidea. Ophiuroidea. Echinoidea, Crinoidea, Holothuroidea, and Concentricycloidea.