1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Bellringer Pretend that you can undergo metamorphosis. Write your responses to the following questions in your science journal: What will you look like when you emerge? How might you find food, and what might you eat? What adaptations that you do not have now might you have after metamorphosis? Chapter 15 Section 3 Arthropods

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Objectives List the four main characteristics of arthropods. Describe the different body parts of the four kinds of arthropods. Describe the two types of metamorphosis in insects. Chapter 15 Section 3 Arthropods

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Characteristics of Arthropods Arthropods share four characteristics: a segmented body with specialized parts, jointed limbs, an exoskeleton, and a well-developed nervous system. Segmented and Specialized Like annelid worms, arthropods are segmented. Many also have specialized parts such as wings, antennae, gills, pincers, and claws. Jointed Limbs Jointed limbs are legs or other body parts that bend at the joints and make moving easier. Chapter 15 Section 3 Arthropods

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Characteristics of Arthropods, continued An External Skeleton The hard, external structure that covers the outside of the body is called an exoskeleton. The exoskeleton supports the body, protects internal organs, and prevents water loss. Sensing Surroundings Arthropods that have compound eyes can see images. A compound eye is an eye that is made of many identical, light-sensitive units. Chapter 15 Section 3 Arthropods

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Kinds of Arthropods Arthropods are classified by the kinds and numbers of body parts they have. An antenna is a feller that sense touch, taste, or smell. Chapter 15 Section 3 Arthropods

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Kinds of Arthropods, continued Centipedes and Millipedes Centipedes and millipedes have one pair of antennae, a hard head, and one pair of mandibles. Mandibles are mouthparts that can pierce and suck food. Centipedes have one pair of legs on each segment and a total of 30 to 354 legs. Millipedes have two pairs of legs on each segment and as many as 752 legs. Chapter 15 Section 3 Arthropods

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Kinds of Arthropods, continued Crustaceans Shrimps, barnacles, crabs, and lobsters are crustaceans. Crustaceans have gills for breathing, mandibles for eating, two compound eyes on eyestalks, and two pairs of antennae. Chapter 15 Section 3 Arthropods

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Kinds of Arthropods, continued Arachnids Spiders, scorpions, mites, and ticks are arachnids. Arachnids have two main body parts: a cephalothorax and an abdomen. Most arachnids have four pairs of legs, no antenna, simple eyes, and mouth parts called chelicerae. Chapter 15 Section 3 Arthropods

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 15 Section 3 Arthropods Body Parts of Arachnids

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Kinds of Arthropods, continued Insects Insects make up the largest group of arthropods. If you put all the insects in the world together, they would weigh more than all the other animals combined! Insects have three main body parts, six legs, and two antennae. Chapter 15 Section 3 Arthropods

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The World of Insects Insect Bodies An insect’s body has three parts: the head, the thorax, and the abdomen. Metamorphosis is a phase in the life cycle of many animals during which a rapid change from the immature form of an organism to the adult form takes place. Complete Metamorphosis Most insects go through a complete metamorphosis. Complete metamorphosis has four parts: eggs, larva, pupa, and adult. Chapter 15 Section 3 Arthropods

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 15 Section 3 Arthropods

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu The World of Insects, continued Incomplete Metamorphosis Grasshoppers and cockroaches are some of the insects that go through incomplete metamorphosis. Incomplete metamorphosis has three main stages: egg, nymph, and adult. Chapter 15 Section 3 Arthropods

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 15 Section 3 Arthropods Incomplete Metamorphosis