The Animal KingdomThe Animal Kingdom

The Animal KingdomThe Animal Kingdom• General CharacteristicsGeneral Characteristics–Multicellular, heterotrophic, diploidMulticellular, heterotrophic, diploid, ,

and are and are motilemotile at some point in at some point in their life cycle.their life cycle.–Embryonic development = germ Embryonic development = germ

tissue layers (ectoderm, endoderm, tissue layers (ectoderm, endoderm, and in most species, mesoderm) and in most species, mesoderm) give rise to adult organs.give rise to adult organs.

Body Plans: Body Plans: SymmetrySymmetry• Asymmetry Asymmetry Radial SymmetryRadial Symmetry

• Bilateral SymmetryBilateral Symmetry•Secondary Secondary Radial SymmetryRadial Symmetry

Body PlansBody Plans

Body PlansBody Plans• Type of GutType of Gut– Sac-likeSac-like, 1 hole for food & waste, 1 hole for food & waste–3-branched gut3-branched gut–One-way systemOne-way system (mouth & anus) (mouth & anus)

Body PlansBody Plans• Body CavitiesBody Cavities– AcoelmateAcoelmate (no internal spaces) (no internal spaces)

–PseudocoelomatePseudocoelomate• hydrostatic skeleton for support & hydrostatic skeleton for support & movementmovement

–CoelomCoelom•Space between mesoderm for Space between mesoderm for organ expansion & attachmentorgan expansion & attachment

Body PlansBody Plans

Body PlansBody Plans• SegmentationSegmentation– Repeating body unitsRepeating body units ((somitessomites))

• Compartmentalization Compartmentalization of tasks of tasks

• Redundant organs in Redundant organs in case of predation or case of predation or damagedamage

EmbryologyEmbryology

• FERTILIZATIONFERTILIZATION

• CLEAVAGECLEAVAGE

• GASTRULATIONGASTRULATION

• ORGAN FORMATIONORGAN FORMATION

Photos by Photos by Anne F. Maben Anne F. Maben

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