Animal Diversity Classification: Level of organization Type of symmetry Germ layers Coelom (+/-, type) Development

Levels of organization Cellular Aggregations of unspecialized cells Tissue Specialized cells separated by membranous layers. Organ Two or more tissues working together

Symmetry Classification by architecture: Asymmetrical, Radial, Bilateral Cephalization

Germ layers Diploblastic Triploblastic Ectoderm Endoderm Mesoderm

Coelom = body cavity Function? Hydrostatic skeleton Space for organ differentiation Protection of organs Freedom of movement

Body cavity (coelom) Acoelomate: Pseudocoelomate: No central body cavity Pseudocoelomate: Coelom derived from endoderm + mesoderm Eucoelomate (coelomate): Coelom lined with mesoderm Platyhelminthes

Development (check your text for illustrations!) Protostome Deuterostome “First mouth” Blastopore = mouth “Second mouth” Blastopore = anus Spiral cleavage, determinate cell division Radial cleavage, indeterminate cell division Schizocoelus (coelom from split in mesoderm) Enterocoelus (coelom from outpocketing of mesoderm)

Segmentation Metamerism: Serially repeated segment Division of labor/specialization Annelids, Arthropods, Chordates

Can you read a tree like the ones we had on the display boards? (Are you sure?) Try and find a tree with these traits: Level of organization, Type of symmetry, Germ layers, Coelom, Development and the major animal phyla to make sure!