Download Notes 10-2

Exploring Life Science
Chapter 10
Mollusks, Arthropods, and Echinoderms
Chapter 10: Mollusks, Arthropods, and Echinoderms
Engage : What is an Arthropod?
Objectives:
1. Identify 4 main groups of arthropods and the main
characteristics of arthropods.
2. Describe how crustaceans, arachnids, and centipedes
and millipedes differ.
10-2 : Arthropods
A. Introduction
1. Greatest number of species.
Greater than 1 million.
Estimated number 1 billion billion.
2. Live: Air, land & H2O
3. 3 characteristics of all arthropods:
a. exoskeleton
b. segmented body
c. jointed appendages
4. Exoskeleton -- rigid outer covering,
waterproof -- provides protection.
Does not grow as the animal grows.
Must be shed & replaced (molting).
5. Segmented -- small number.
6. “Jointed Legs” = arthropods.
Antennae, claws, walking legs & wings.
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Exploring Life Science
Chapter 10
Mollusks, Arthropods, and Echinoderms
7. Open circulatory system -- blood is not contained
within small tubes.
Blood carries food.
8. Respiratory Organs -- gills, book lungs, air tubes.
9. Reproduce -- sexually. Usually egg
and sperm unite inside female’s body.
10. Crustaceans, centipedes, millipedes,
spiders & insects.
B. Crustaceans
1. Characteristics
a. Hard exoskeleton
b. 2 pair of antennae
c. Mouth parts -- crushing & grinding food.
d. Gills
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Exploring Life Science
Chapter 10
Mollusks, Arthropods, and Echinoderms
2. Examples
a. Hermit crab, crabs, lobsters, barnacles &
shrimp.
3. Can regenerate.
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Exploring Life Science
Chapter 10
Mollusks, Arthropods, and Echinoderms
C. Centipedes & Millipedes
1. Characteristics -- Many legs
Centipedes -- 1 pair of legs/segment
Millipedes -- 2 pair of legs/segment
2. Different
Centipedes – Carnivores (meat-eaters)
Millipedes – Herbivores (plant-eaters)
3. Centipedes – Inject poison
4. Exoskeleton – Not waterproof
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Exploring Life Science
Chapter 10
Mollusks, Arthropods, and Echinoderms
D. Spiders & Their Relatives
1. Arachnids – Spiders, scorpions, ticks & mites.
2. Characteristics
a. 2 segments -- head & abdomen.
b. 8 legs.
3. Feeds on insects (mostly).
4. Capture
a. Webs -- silk
b. Hide
5. Injects venom -- fangs.
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Exploring Life Science
Chapter 10
Mollusks, Arthropods, and Echinoderms
6. Scorpions – Live in desert areas.
7. Ticks & mites – Parasites.
Spread diseases (i.e., Rocky Mountain
Spotted Fever, Lyme Disease).
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