Sessile
Gastrulation
Bilateral Symmetry
Diplo vs. triploblastic
Radial symmetry
Cell morphology
Monophyletic
Paraphyletic
Polyphyletic
Clade
Embyrogenesis
Cellular differentiation
Protostomes
Deuterostomes
Cephalization
concentration of sensory organs, nervous tissues, and feeding at ANTERIOR (front) end of animal