1. Introduction to Animals

2. Unifying Characteristics
Eukaryotic
Heterotrophic
Carnivores, parasites, filter feeders, detritus feeders
Multicellular
Lacking cell walls and chloroplasts
Respiration – consume oxygen and give off carbon dioxide

3. More Unifying Characteristics
Movement
Reproduction
Produce egg and sperm in multicellular structures
Specialized cells

4. Body Structure Body structure basically a hollow tube
Inside of tube is specialized for digesting and absorbing food (may be closed)
Outer part responds to the environment
Space in between may also be specialized
Internal transport in larger animals (circulation)
Excretory systems in larger animals

5. Symmetry Asymmetric Radial symmetry Bilateral symmetry
Has no symmetry (usually simplistic)
Ex. sponges
Radial symmetry
All wedge shaped sections around a vertical line are similar
Ex. starfish
Bilateral symmetry
Only one plane that can divide the body into equal parts
Tend to have a head region (anterior) for quick response to stimuli
Ex. Butterflies, humans
Other terminology: posterior (“butt”), dorsal (back), ventral (front)

6. Two Major Divisions
Vertebrates (backbone)
Invertebrates (no backbone)

7. Trends Cell specialization Levels of organization
More complex symmetry
Cephalization
Body cavity formation