1. Introduction to Animal Diversity !

2. and more animal diversity!

3. Make a hypothesis: How are these 9 animal phyla related
Make a hypothesis: How are these 9 animal phyla related? Draw an evolutionary tree with 9 branches…
Arthropods
(insects, spiders,
crustaceans)
Nematodes
(roundworms)
Annelids
(segmented worms)
Chordates
(mostly vertebrates)
Platyhelminthes
(flatworms)
Porifera
(sponges)
Mollusks
(snails to squids)
Echinoderms
(sea stars, sea urchins)
Cnidaria
(jellies)

4. What do all animals have in common?
Eukaryotic & multicellular with no cell walls
Heterotrophs that ingest food
Specialized cells capable of movement

5. Symmetry in Animals
Bilateral Radial

6. Many bilaterally symmetrical animals show cephalization - a concentration of senses and brain in the head region

7. Animal Body Plans True digestive system Gastrovascular cavity
performs dual functions of digestion and gas exchange

8. Protostomes vs. Deuterostomes (which comes first, mouth or anus?)

9. Tissue Organization
Tissue - a collection of specialized cells with a common structure and function
- separated from other tissues by a membraneous layer
- Ex: muscle tissue, nervous tissue
- most (but not all!) animals have specialized tissue layers

10. Tissue Layers Form during embryological development (gastrulation)
Blastula (ball of cells) develops germ layers
Ectoderm - Endoderm - Mesoderm
Embryos with two layers (ecto and endo only) are diploblastic
Embryos with all three layers are triploblastic

11. Diploblast
Triploblast
Ectoderm
Endoderm
Mesoderm

12. Some triploblastic animals have a coelom – a hollow cavity lined with mesoderm tissue that contains internal organs

15. Segmentation
Segment - a distinct section of the body; may be repeating (annelids) or differentiated (arthropods)

16. Skeletons
Endo
Exo
Hydrostatic