1. Arthropods and Echinoderms
Animals
Chapter 2 sections 3 & 4

2. Characteristics of Arthropods
75% of all known species
Jointed limbs
Segmented body
Exoskeleton
Well developed nervous system

3. Jointed Legs
Arthro means jointed
Pod means foot

4. Segments Some have virtually identical segments (millipede)
Some have very different segments (grasshopper)

5. Exoskeleton External skeleton made of chitin
Sheds to allow growth in a process called molting
Keeps organism from drying out
Protects organism
Helps with movement

6. Nervous System Head and brain
Some have simple eyes that can detect light but not make an image
Most have compound eyes that allow them to see images
Bristles that sense movement, vibrations, chemicals

7. Centipedes and Millipedes
Carnivores
1 pair of legs per segment
One pair of antennae
Millipedes
Herbivores
Two pairs of legs per segment
One pair of antennae

8. Crustaceans Shrimp, barnacles, crabs, lobsters Gills
Two pair of antennae
Eyes on stalks

9. Arachnids Spiders, scorpions, mites, ticks Two main body parts:
cephalothorax – head
and thorax (chest)
combined
abdomen – stomach
area
No antennae
Four pairs of walking legs
Chelicerae instead of mandible (pinchers instead of jaw)
Eight simple eyes

10. Insects Largest group of arthropods
Live everywhere on earth except oceans
Good because pollinate flowers
Bad because they are pests, eat crops, can carry disease
Three part body – head, thorax, abdomen
Some have wings

11. Metamorphosis- A change in form from egg to adult
Incomplete metamorphosis- egg, nymph, adult
Baby looks like small adult

12. Metamorphosis continued
Complete metamorphosis
Full change from egg to adult
Four stages – egg, larva, pupa, adult

15. Echinoderms Term means “spiny skinned”
Has Endoskeleton which is inside the body
Water vascular system – water pressure helps with feeding, breathing and movement