-
Symmetry
- Radial
- Bilateral
- Asymmetrical
-
Acoelomate
No body cavity
-
Pseudocoelomate
- Body cavity develops between mesoderm and endoderm
- Not a true coelomate
-
Coelomate
Body cavity entirely within the mesoderm
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Protosome
- Spiral cleavage
- Determinate cleavage
- Blastospore develops into mouth
- Second opening later turns into anus
- Schizocoelous coelom formation
- Ex. Mollusks, Annelids, Athropods
-
Deuterostomes
- Radial cleavage
- Indeterminate cleavage
- Blastospore develops into anus
- Second opening turns into mouth
- Entercoeleous coelum formation
- Ex. Echinoderms, Chordates
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Phylum Porifera
- Sponges
- Osculum-Large opening/pore
- Centra cavity
- Collar cells-resembles protist with single flagellum
- Intracellular digestion
- Loost aggregate of cells
- Scypha-sponges
-
Phylum Cnideria
- Most marine, some freshwater
- Tissue grade level of organization
- Two tissue layers
- Single digestive opening
- Radial symmetry
- 2 body types
- -polyp
- -medusae-jellyfish
- Class hydrozoa (hydras), scyphozoa (jellyfish), anthozoa (sea anemones)
-
Phylum Playhelminthes
- Class Turbellaria
- Free living flatworms-not parasitic
- Bilateral symmetry
- Acoelamate
- Single opening digestion
- Example: Dugesia
-
Phylum Playhelminthes
- Class Cestoda
- Possess a scolex armed with suckers and hooks
- Posterior of scolex is a long ribbon of units called proglottids
- -Reproductive
- No digestive system
- Includes intermediate hosts (vertebrates)
- Example: tapeworms
-
Phylum Nematoda
- Roundworms
- Parasite of mammals
- Bilateral symmetry
- Pseudocoelomate
- Tubular digestive tract
- Example: Ascaris
-
Phylum Annelida
- Coelomate
- Tubular digestion
- Closed circulatory system
- Bilateral symmetry
- Three classes...
-
Class Oligochaeta
- Annelid
- Lives in soil
- Earthworms
-
-
Class Hirudinea
- Annelida
- Freshwater
- Carnivores
- Leeches
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