1. Exoskeleton
Hard, tough outer covering that provides framework and support
Made of chitin

2. Endoskeleton
Internal skeleton

3. Inner layer of cells in the gastula Develops into digestive tract
Endoderm
Inner layer of cells in the gastula
Develops into digestive tract

4. Outer layer of cells in the gastula
Ectoderm
Outer layer of cells in the gastula
Develops into outer coverings and the nervous system

5. Develops into skeletons and muscles
Mesoderm
Between the 2 -derms
Develops into skeletons and muscles

6. Coelom
Fluid filled cavity
Provides open space inside of body

7. multiple body components
Segmentation
“put together”
multiple body components

8. Animals with anterior (head) & posterior (tail)
Cephalization
Animals with anterior (head) & posterior (tail)
Concentrate nervous and sensory organs at the anterior
Development of a specialized head

9. Asymmetry
Irregular shape
Ex. Sponge

10. Radial symmetry
Body plan in which parts repeat around an imaginary line drawn through the center
Ex. Cnidarians
(jellyfish)

11. Bilateral Symmetry
Body plan in which left and right sides are identical when an imaginary line is drawn through the center
Ex. Flatworm

12. Sponges Sessile: live entire adult life attached to a single spot
Very simple: no mouth, no organ systems
Rely on the movement of water through their bodies for
respiration, circulation, and excretion

13. Cnidarians Soft-bodied, carnivorous, stinging tentacles
Simplest animals to have body symmetry and specialized tissues

14. Platyhelminthes (Flatworms)
Soft, flattened worms
Simplest organisms to have cephalization

15. Nematoda (Roundworms)
Unsegmented worms
Have pseudocoeloms and digestive systems with two openings
Many are predators
Some act as parasites that affect humans

16. Mollusca Soft-bodied Usually have an internal or external shell
Based on their shape, what is their symmetry?

17. Annelida (Segmented Worms)
Worms with segmented bodies
Have a true
Based on their shape, what is their symmetry?

18. Arthropoda
Have a segmented body, tough exoskeleton, jointed appendages
Exoskeleton
Hard, tough outer covering that provides framework and support
Made of chitin

19. Arthropoda - Crustaceans
Two pairs of antennae, and two or three body sections
Have chewing mouthparts called mandibles

20. Arthropoda – Arachnids (Chelicerates)
Have mouthparts called chelicerae
Two body sections
Nearly all have four pairs of walking legs
Based on their shape, what is their symmetry?

21. Arthropoda - Insects Jaws One pair of antennae Three-part bodies
head, thorax, abdomen
legs attached to thorax

22. Echinodermata Sea Cucumber Sea Urchin Spiny skin Internal skeleton
Water vascular system
Suction-cup “feet”
Sea Urchin