Bio1151b Chapter 32 An Introduction to Animal Diversity
  1. Animals are multicellular,                eukaryotes.
  2. The ancestor of animals diverged from those of        about 1.2 billion-800 million years ago, and may have resembled modern                    .
  3. The kingdom diversified during the           explosion, when many animal phyla appeared.
  4. Animals can be categorized by how their cells are organized according to a       plan.
    •         symmetry is like a flower pot, the body radiates from the center.
    •            symmetry has a single plane of symmetry.
    • Most animals have          that develop from embryonic layers of the           .
    • Diploblastic animals such as jellyfish have      germ layers:           and           . Triploblastic animals have        germ layers, including a           .
    • The mesoderm may develop into tissue that line a fluid–filled space called a         .
      • A               is a body cavity only partially lined by mesoderm tissues.
      • Organisms without a body cavity are considered              .
  5. The coelomates show two major modes development.
    • Protostomes develop their        from blastopore of the gastrula.
    • Deuterostomes develop their       from the blastopore.
  6. Current phylogeny places            as a clade with true          , and divides the            into three clades:                , Lophotrochozoa, and Ecdysozoa.