02-25-08

02-25-08 - o Deuterosome Anus from blastopore mouth...

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o Deuterosome Anus from blastopore mouth elsewhere Radial cleavage Soelom-pouches off archenteron. Mesoderm derives from pouch tissue individual blastomere doesn’t have set fait, it can become anything o Major groups Echinoderms Chorodates Phylum echinodermata o 13,000 species, rich fossil record o Origins ~540 mya early Cambrian o Defining characteristics Calcareous endoskeleton: ossicles Pentaradial adults, bilateral larvae (star fish) Water vascular system: unique (chambers filled with water, but not similar to sponges) Complete gut (usually) NO excretory organs So Diffusion-phagocytosis of particulates No osmotic regulation-marine (no way of regulating) Respioration and circulation 3 components Hemal system water vascular system coelomic cavities o Systems of tubes chambers cilia pumps o Diffusion Sea cucumbers (exception)-rectal respiratory structure Nervous system- decentralized ring – no head Reproduction and development
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This note was uploaded on 04/08/2008 for the course BIS 1b taught by Professor Kimsey during the Winter '08 term at UC Davis.

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02-25-08 - o Deuterosome Anus from blastopore mouth...

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