1. Arthropods 5 th Grade

2. Phylum: Arthropod - “Arthropoda” *4 major groups: 1) Crustaceans 2) Arachnids 3) Centipedes & Millipedes 4) Insects

3. DEFINING Characteristics that arthropods have: (what makes them unique) Invertebrates –(no backbone) Exoskeletons –(external skeleton) Segmented Bodies Jointed Appendages Most have antenna

4. Characteristics that arthropods have that they share with other organisms: Bilateral symmetry Open circulatory system One way digestive system (2 openings) Most reproduce sexually

5. Exoskeleton: hard outer shell or skeleton

6. Exoskeleton – Advantages and Disadvantages PROS: 1)Protects the body 2)Prevents water from evaporating so the insect does not dry out CONS: 1)Limits movement 2)Have to lose shell and regrow a new one in order to grow

7. Since their exoskeletons prevent arthropods from moving or growing quickly, what do they use to help them move and grow? *Other body parts help them move: 1)segmented bodies 2)jointed appendages Some undergo a process called “molting” Molting = the process of shedding an outgrown exoskeleton and growing a new one that is larger

8. Adaptations for Movement Segmented Bodies: Jointed Appendages:

9. Molting: the process of shedding an outgrown exoskeleton and growing a new one that is larger

10. Most arthropods have an antenna Antenna: an appendage attached to the head that contains sense organs

11. ALL arthropods have Bilateral Symmetry

12. Open Circulatory System Closed Circulatory System ARTHROPODS have an OPEN CIRCULATORY SYSTEM

13. Look for the one way digestive system (2 openings) and the open circulatory system

14. Largest Arthropod Groups CharacteristicCrustaceansArachnidsCentipedes and Millipedes Insects Number of Body Sections 2 or 3223 Pairs of Legs5 or more4Many3 Pairs of Antennae 2NONE11

15. Examples of Crustaceans Crayfish Lobster Shrimp Pill bug

16. Examples of Arachnids Spiders Mites Scorpions Ticks

17. Examples of Insects Fly Butterfly Ant Grasshopper

18. Centipedes and Millipedes