Invertebrates & Joint-Legged Animals SBI 3U October 18th, 2012 Ms.Zafar
Invertebrates Animal grouping No backbone Heterotrophic Why don’t they have cell walls?
We will be studying… Phylum Mollusca Phylum Echinodermata
Phylum Mollusca Shell Marine or terrestrial Annelid-like ancestors
Body Plan Foot Mantle Visceral Mass
3 Classes Bivalva Cephalopoda Gastropoda
Class Bivalva Shell-fish Two-part shell Why do they not need an anterior end? Gills
Class Gastropoda Diverse Big foot Radula Gills Which mollusks have a lung?
Class Cephalopoda Shell movement Brain development What has happened to the cephalopod’s shell?
Phylum Echinodermata Marine Symmetry shift Why might Echinoderms have radial symmetry as adults? Endoskeleton
Joint-Legged Animals
Joint-Legged Animals Arthropods
Phylum Arthropoda Segmented body Exoskeleton Hemocoel Coelom Gas exchange – gills & trachea
Moulting in Arthropods Exoskeleton limits size
Open Circulatory System Hemocoel Ancient annelids developed blood instead of body fluid