Phylum Echinodermata

Phylum Echinodermata - Phylum Echinodermata - Spiny-skinned...

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Phylum Echinodermata - Spiny-skinned - Marine - Pentaradial symmetry - Have spines or calcareous plates in their skin - They have a water vascular system used for locomotion, respiration, and food acquisition HOW ECHINODERMS ARE LIKE HUMANS - Enterocoelous formation of the coelom- the coelom develops from pouches that bud off the archenteron (dueterostomes- second opening becomes the mouth) (protostomes have schizocoelom- meaning that a solid mass of mesoderm splits creating the body cavity) - Exhibit radial, indeterminate cleavage of the early embryo o Radial cleavage- the cleavage planes are parallel or perpendicular to the vertical axis of the zygote o Spireal cleavage (in protostomes)- the cleavage planes are diagonal o indeterminate cleavage- each cell of an early embryo has the ability to develop into a complete embryo o determinate cleavage- (protostomes)- the fate of the cells are determined already - are duterstomes FIVE CLASSES - Class Asteroidea- sea star and star fish- five to twenty five-armed attached to a central disk; flexible and spiny - Class Crinoidea- sea lilies. Flower-like body with numerous branched arms - Class Echioidea- sea urchins and sand dollars. Dermal plates fused to form a
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This test prep was uploaded on 04/20/2008 for the course BIO 112 taught by Professor Godsel during the Spring '08 term at Loyola Chicago.

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Phylum Echinodermata - Phylum Echinodermata - Spiny-skinned...

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