I. Characteristics of Animals
• All animals are: eukaryotic, multicellular, and heterotrophic
• Type of nutrition: heterotrophs
• Do animals have cell walls? no
• Most reproduce sexually but some can reproduce asexually (e.g. hydra,starfish)
II. Animal Body Plans
• Three types of body symmetry:
1. Radial- jellyfish
2. Bilateral- Planarians
3. Asymmetrical- Sponges
• Germ layers:
1. Diploblastic have two germ layers, ectoderm and endoderm
2. Triploblastic means animals that have 3 germ layer- ectoderm, endoderm and mesoderm
• Body cavities:
o Acoelomate: no body cavity (example: flatworm)
o Pseudocoelomate: fluid-filled but not fully lined (example: roundworm)
o Coelomate: fluid filled and fully lined(example: arthropods)
III. Developmental Patterns
• Sequence: germ layers → body symetry→ presence and absence of body cavity
• Protostome vs Deuterostome:
o Protostome: mouth develops from mouth to anus (examples: slug, butterfly,
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o Deuterostome: anus develops from anus to mouth fish, amphibians, reptiles, birds and mammals.
IV. Major Animal Phyla
Fill in one key trait and example for each phylum below:
Phylum
Key Trait
Example(s)
Porifera
No true tissues
Sponges
Cnidaria
Stinging cells, radial symmetry, polyp
or medusa
Jellyfish (Medusa) and Sea anemone (polyp)
Platyhelminthes
dorsoventrally flattened, unsegmented
bodies, bilateral symmetry, and lack
of a true body cavity (acoelomate)
Flatworms, planarians
