1. Kingdom Animalia

2. Characteristics of Animals Eukaryotic cells – have a nucleus and membrane bound organelles Heterotrophic – must ingest their food Diploid – two copies of each chromosome Multicellular – made of many cells Forms a Blastula – a hollow ball of cells

3. Characteristics of Animals Motile – can move during at least one stage of life Some that do not move during a stage of life are called sessile See Visual Concepts Ch 28 “Reproduction in Jellyfish”

4. Animal Body Plan Animals are described according to their arrangement of body symmetry Asymmetry - irregular shape Radial symmetry - arranged around a central axis Bilateral symmetry - there are distinctive right and left halves

5. Animal Body Plan Body Planes Dorsal - upper Ventral - lower Anterior - front Posterior - rear

6. Internal Body Cavity Acoelomates – have no body cavity; filled with tissue (ex: flatworms) Pseudocoelomates – have a body cavity located between the mesoderm and endoderm (roundworms) Coelomate – have a true coelom, a body cavity located entirely within the mesoderm (segmented worms, and higher animals including humans) Ectoderm Mesoderm Endoderm