Invertebrates & Joint-Legged Animals

SBI 3UOctober 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