Bio CHP. 32,33 notes

Bio CHP. 32,33 notes - I -Phylum Porifera Characteristics...

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I -Phylum Porifera Characteristics Body loose aggregation of cells no internal organs of body structure all are aquatic all filter feeders Spongocoel: cavity inside sponge; leads outside lined with cells-everything happens at cellular level Choanocytes: serves both digestive and reproductive functions Sponge Feeding Spongocoel lined with choanocytes Choanocytes collect food particles on collars and digests them Intracellular digestion (phagocytosis) Sponge Reproduction Usually asexual (mitotic budding) Monoecious: both males and females within same individual Choanocytes can become gametes and reproduce sexually “Sperm” swim away from sponge Fuse with an “egg” of a different sponge Fused choanocytes divide mitotically and develop into free-swimming gemmule larva PORIFARA CELL Spicule: sponge skeleton; made of calcium or silica Sporgocytes: secret sponging Spongin: soft material surrounding spicules made of collagen Porocytes: become the holes in the sponge wall Amoebocytes- transports nutrients to other sponge cells Can also become gametes “only eggs” Most Primitive of Animals Sponges likely evolved from a colony of protests Mainly phyla Choanozoa and Amoebozoa II Phylum Cnidaria Characteristics Diploblastic: two distinct body layers with muscle between them Outer layer: Epidermis (ectoderm) Inner layer: Gastro dermis (endoderm) Radial Symmetry: can divide into equal halves along any plane Round Gastrovascular Cavity: true extracellular digestive system Mouth and anus are the same opening
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This note was uploaded on 04/22/2008 for the course BIO 200 taught by Professor Cooper during the Spring '08 term at Hillsdale.

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Bio CHP. 32,33 notes - I -Phylum Porifera Characteristics...

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