bio chapter 31

  1. What are two facts about corals?
    • -Most corals have a symbiotic relationship with algae.
    • -Corals are threatened by global warming and pollution.
  2. Anthozoa:
    -Polyp dominates life cycle (many associated with clownfish)
  3. Scyphozoa:
    • -Medusa dominates life cycle
    • -All marine
    • -Some are extremely poisonous
  4. Hydrozoa:
    • -Marine or freshwater
    • -Some exist as polyps only others as medusa only
    • -Most are colonial (hydranth, gonangium, Obelia medusa)
  5. Three classes of cnidarians:
    • -Hydrozoa (hydrozoans)
    • -Scyphozoa (true jellyfish, jellies)
    • -Anthozoa (sea anemones & corals)
  6. Cnidarians:
    • -Radial symmetry
    • -Diploblastic
    • -Two basic body plans: poly(sessile) and medusa (motile)
    • -Reproduce sexually
    • -Carnivorous
    • -Nerve net
    • -Gastrovascular cavity
    • -Possess unique stinging cells (cnidocytes)
  7. Ctenophores (comb jellies):
    • -Radial symmetry
    • -Diploblastic (epidermis and endodermis) with a mesoglea
    • -Bioluminescent
    • -8 rows of comb-like plates (ctenes) composed of fused cilia
    • -Reproduce sexually
  8. 3 major groups of sponges:
    • -Demosponges (most)
    • -Glass sponges
    • -Calcareous sponges
  9. Sponges:
    • -Simplest animals
    • -Lack true tissues; have specialized cells (choanocytes, amoebocytes)
    • -Adults sessile
    • -Body porous
    • -Skeletal elements: spicules (SiO2 or CaCO3) AND/OR sponging (protein).
    • -Filter feeders
    • -Flow of water? Interior
    • -Reproduce asexually (budding/ fragmentation) or sexually (monecious/ dioecious)
  10. Animal Phylogeny
    • -Sponges
    • -Ctenophores (comb jellies)
    • -Cnidarians
  11. Eumetazoans-
    true tissues and exhibit symmetry
  12. Parazoans-
    no true tissues (sponges)
  13. Animal Phylogeny:
    Animal and fungi believed to have arisen from a common ancestor in opisthokont clade.
  14. Parasitic life cycles are complex
    -Must overcome hosts defenses.

    -Must be able to disperse to new host while current host is living.

    -Most have one or more intermediate hosts and several larval stages.
  15. No life cycle maximizes all benefits
    -Characteristic or stage may improve performance in 1 activity, but reduce performance In another (trade-off)

    -Females can produce many small eggs or few large eggs.

    -Altricial young (must depend upon parents) vs. precocial young (able to act like adults almost immediately)
  16. All have at least one dispersal stage. Explain further?
    • --Sessile adults typically disperse as eggs or larvae.
    • --Motile adults disperse when mature.
  17. Explain the whether the Development is indirect or direct?
    • -- Indirect – organism has distinct larval/nymph stage or goes thru metamorphosis; different stages specialized for different functions.
    • -- Direct – no distinct larval/nymph stage or no metamorphosis; young resemble adults.
  18. What are the animal life cycles?
    • 1. Development is indirect or direct
    • 2. All have at least one dispersal stage
    • 3. No life cycle maximizes all benefits
    • 4. Parasitic life cycles are complex
  19. Detritivores/scavengers
    will primarily anything, holding nutritional value.
  20. Omnivores
    will primarily anything, holding nutritional value.
  21. Parasites:
    derive nutrition from animal host; usually do not kill host; much time and energy devoted to dispersal.
  22. Predators:
    capture and kill large animal prey
  23. Herbivores:
    feed on plants; usually have long, complex guts.
  24. Filter feeders:
    filter small organisms and organic molecules from their environment; may be sessile or motile.
  25. What are the feeding strategies?
    filter feeders, herbivores, predators, parasites, omnivores, detritivores/scavengers
  26. External appendages do what?
    enhance locomation
  27. Body segmentation does?
    • -Allow better control of movement.
    • -May not be apparent externally
Card Set
bio chapter 31
animal origins and body plans