Feb 27 Deuterstome phyla

Feb 27 Deuterstome phyla - Duterostome Phyla Sea urchins,...

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Duterostome Phyla Sea urchins, Starfish, Sea squirts, Vertebrates etc. Duterostome characteristics Radial cleavage – vertically aligned tiers of cells Indeterminate cleavage – plasticity in cell lineages Enterocoelous - coelom developed from out pocketing of the gut Blastopore becomes anus => Dutero stome Body forms highly diverse “worms” to birds Phyla Echinodermata Hemichordata Chordata _________________________________________________________________________________ Phylum Echinodermata About 6500 species all marine with six living classes but about 20 extinct ones KEY FEATURES ‘Radial” Duterostomes CaCO 3 (calcite) endoskeleton made up of more or less well fused plates or ossicles which often have spines (“echino-“) Five part radial symmetry ("pentaradial") Water vascular system comprised of radial canals, madreporite , stone canal and tube feet with ampullae Movement is by the tube feet , spines or movements of the "arms" Nerve ring with (5) radial nerves Feeding through a terminal mouth which differs among the classes
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Feb 27 Deuterstome phyla - Duterostome Phyla Sea urchins,...

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