Chap 31 notes

Chap 31 notes - Animal Kingdom: Deuterostomes Includes:...

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Animal Kingdom: Deuterostomes Includes: echinoderms (starfish), and chordates (humans and vertebrates) Hemichordates as well: proboscis, collar and trunk (acorn worms) Characterized by several shared derived characters (synapomorphies) Radial cleavage, indeterminate cleavage (fate of cells fixed later) Blastopore becomes the anus | pharyngeal gill slits Echinoderms Bilaterally symmetrical, ciliated Pentaradial symmetry Water vascular system : feeding and gas exchange and serves as a hydrostatic skeleton Tube feet: ampulla at the base (stores fluid and operates foot) Endoskeleton: internal skeleton covered by a ciliated epidermis “Spiny Skinned” Well developed Coelom, complete digestive system No excretory organs are present | No Brain Fertilization takes place in water | They are found in all depths of the ocean Class Asteroidea Starfish, Central disc, mouth lies in the center of the underside of the disc Endoskeleton: calcareous, permit some movement in arms Delicate dermal gills, small extensions of the body wall, carry out gas exchange Coelomic fluids, which fills the Coelom and bathes the internal tissues, circulation Class Ophiuroidea Basket stars, brittle stars, central disc in arms Tube feet used for sensory function (maybe taste) Class Echinoidea Skeletal plates are flattened and fused to form a solid shell (TEST) Phylum Chordata Urochordata (tunicates), Cephalochordata (lancelets), Vertebrata (backbones) Coelomates, bilateral symmetry, a tube-within-a-tube-body plan, 3 germ layers Endoskeleton and a closed circulatory system with a ventral heart, segmented bodies Pharyngeal slits: gills arch and groove develop in the throat region| gas exchange Subphylum Urochordata
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Tunicates (sea squirts), Ascidians Expanded body has a pharynx with slits, zooplankton members Loses its tail, notochord, and much of its nervous system Only pharyngeal slits, Endostyle and structure distinguish this as a chordate Protective covering: Tunic (carbohydrate, two openings) Incurrent siphon: water and food enter
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Chap 31 notes - Animal Kingdom: Deuterostomes Includes:...

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