Bio chapter 31

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Bio chapter 31
2010-11-04 20:31:32
bio chapter

animal origins and body plans
Show Answers:

  1. What are the body cavity functions?
    • -- Cushions suspended organs
    • -- Acts as a hydrostatic skeleton against which muscles can work (soft-bodied animals
  2. Coelomate?
    • mesoderm surrounds body cavity (coelom) and organs
    • (Ectoprocts, nemerteans, phoronids, brachiopods, annelids, mollusks and arthropods)
  3. Pseudocoelomate?
    mesoderm surrounds body cavity (pseudocoel) but not internal organs
  4. Acoelomate?
    • no fluid-filled body cavity
    • (Flatworms)
  5. The body cavity is locate where?
    located between digestive tract and outer body wall
  6. What are the types of body cavity's?
    Acoelomate, Pseudocoelomate, Coelomate
  7. What is an example of bilateral symmetry?
    • (cnidarians and ctenophores)
    • Any plane along central axis divides animal into similar halves.
  8. What is an example of bilateral symmetry?
  9. Only 1 plane through midline divides animal into mirror-image halves.*cephalization
  10. What is an example of asymmetrical symmetry?
  11. What are the types of symmetry?
    asymmetrical, bilateral, radial
  12. Animal body plans vary in four features. What are these four features?
    symmetry, body cavity, body segmentation, external appendages
  13. Characteristics of animals are?
  14. · Muliticellular, heterotrophic eukaryotes
    • · Ingest food and digest internally
    • · Cells lack cell walls
    • · Most have tissues and capable of movement
    • · Most reproduce sexually (diploid stage usually dominates life cycle)
    • · In most, a small flagellated sperm (n) fertilizes a larger, nonmotile egg (n) to form a zygote (2n)
    • · Embryonic development regulated by Hox genes; includes cleavage and gastrulation
  15. What 2 groups are triploblastic animals divided into?
    protosomes and devitrosomes