1. The Animal Kingdom

2. General CharacteristicsGeneral Characteristics –Multicellular, heterotrophic, diploid, and are motile at some point in their life cycle. –Embryonic development = germ tissue layers (ectoderm, endoderm, and in most species, mesoderm) give rise to adult organs.

3. Body Plans: Symmetry Asymmetry Radial SymmetryAsymmetry Radial Symmetry Bilateral SymmetryBilateral Symmetry Secondary Radial SymmetrySecondary Radial Symmetry

4. Body Plans

5. Type of GutType of Gut – Sac-like, 1 hole for food & waste –3-branched gut –One-way system (mouth & anus)

6. Body Plans Body CavitiesBody Cavities – Acoelmate (no internal spaces) –Pseudocoelomate hydrostatic skeleton for support & movementhydrostatic skeleton for support & movement –Coelom Space between mesoderm for organ expansion & attachmentSpace between mesoderm for organ expansion & attachment

7. Body Plans

8. SegmentationSegmentation – Repeating body units (somites) Compartmentalization of tasksCompartmentalization of tasks Redundant organs in case of predation or damageRedundant organs in case of predation or damage

9. Embryology FERTILIZATION FERTILIZATION CLEAVAGE CLEAVAGE GASTRULATION GASTRULATION ORGAN FORMATION ORGAN FORMATION

11. Photos by Anne F. Maben © 2000 All rights reserved These images are for viewing only and may not be published in any form