1. Arthropods
Chapter 13 Section 3

2. Arthropods Jointed appendages, Bilateral symmetry Segmented bodies
Exoskeleton
Body cavity
Digestive system with two openings
Nervous sytsem
MOST have separate sexes (not hermaphrodites)

4. Arthropods
Some many segments, others have fused segments forming body regions
A hard, thick, outer covering called an exoskeleton covers, supports, and protects the arthropod, it is shed and replaced occasionally in a process called molting

5. Insects
3 body regions

6. Insect body regions
An insect’s head has a pair of antennae, eyes, and a mouth
The thorax has three pairs of legs; if the insect has wings, they are attached to the thorax
The abdomen contains reproductive structures and an open circulatory system; insects obtain air and release waste gases through openings called spiracles

8. Metamorphosis
Series of body changes as insects become adults

9. Incomplete metamorphosis
Egg, nymph adult

10. Complete metamorphosis
Egg, larva, pupa, adult

11. Metamorphosis
Insects eat plants, blood of animals, nectar, decaying materials, wood, and clothes; mouth parts are diverse and adapted to diet
Insects are successful due to their exoskeletons, ability to fly, rapid reproductive cycles and small sizes

12. Arachnids
Spiders and ticks have two body regions (the cephalothorax and abdomen), four pairs of legs, and no antennae

13. Scorpions
Sharp, poison-filled stinger at the end of their abdomen

14. Spiders
Inject their prey with enzymes to digest it.

15. Mites and Ticks
Generally parasites; ticks often carry diseases

16. Centipedes and millipedes
Long bodies with many segments, many legs, antennae, and simple eyes

17. Crustaceans
Crabs, shrimp, and barnacles have one or two pairs of antennae and mandibles for crushing food

18. What arthropods can do! Food source
Aid in agriculture, important part of ecological communities in which humans live
BAD 
Some are pests that carry disease or damage property

19. Insecticides
Can kill insects, but cause other environmental problems; biological methods for controlling insects are being developed

20. Arthropod fossils Some fossils are more than 500 million years old
Probably evolved from a segmented worm ancestor.