Name Date Class

Arthropods

Section 28.1 Characteristics of Arthropods

In your textbook, read about what an arthropod is and exoskeletons.

Answer the following questions.

1. What is the most distinguishing arthropod characteristic?

2. Explain the advantage of having appendages with joints.

3. List three functions of an arthropod exoskeleton.

In your textbook, read about molting, segmentation, and gas exchange.

Complete each statement.

4. Prior to molting, a new exoskeleton forms ______the old one.

5. Many arthropods have three distinct body sections: a(n) ______, a(n) ______, and a(n) ______.

6. In arthropods that have a ______, the head and thorax are fused. Complete the table by checking the correct column to indicate the respiratory structure you would expect to find in each example.

Type of Respiratory Structure

Example Book Lungs Gills Tracheal Tubes

7. freshwater crayfish

8. tarantula

9. hissing cockroach

10. swallowtail butterfly

In your textbook, read about arthropods' senses, body systems, and reproduction.

Identify the following as characteristics of either simple or compound eyes.

______11. have multiple lenses

______12. well-adapted for detecting slight movements

______13. have a single, focusing-type lens

______14. produce an image made up of thousands of parts

If the statement is true, write true. If it is not, rewrite the italicized part to make it true.

15. Animals produce pheromones, or low frequency sounds, that affect the behavior of others.

16. In many arthropods, large, fused ganglia act as nervous system control centers for the entire body.

17. Arthropods have an open circulatory system, in which blood leaves vessels and comes in direct contact with body tissues. ______

18. Respiration occurs in arthropods via the Malpighian tubules. ______19. During parthenogenesis, fertilized eggs develop into offspring. ______

Section 28.2 Diversity of Arthropods

In your textbook, read about arthropod origins.

Answer the following questions.

20. What are the major reasons for the widespread success of arthropods?

21. From what animal group did arthropods probably evolve?

22. List three adaptations that have evolved in arthropods.

In your textbook, read about arachnids.

Circle the letter of the response that best completes the statement.

1. An animal that is not a member of the class Arachnida is a. a spider. b. a deer tick. c. a walking stick. d. a dust mite. 2. In spiders, chelicerae are highly modified appendages that are adapted for a. holding food and injecting poison. b. spinning silk and weaving webs. c. chewing food. d. mating and reproduction. 3. The appendages of a spider that function as sense organs are a. its chelicerae. b. its pedipalps. c. its legs. d. its spinnerets. 4. After catching their prey and injecting it with poison, spiders a. eat the prey whole. b. lay their eggs in the prey. c. chew the prey into small pieces. d. suck up the prey's contents, which have been liquified with enzymes. 5. In ticks and mites, the head, thorax, and abdomen a. are absent. b. are well-defined. c. are fused into one section. d. are all the same size. 6. The fact that horseshoe crabs have remained relatively unchanged for 500 million years indicates that

a. natural selection has not taken b. they must reproduce by place. parthenogenesis. c. they have very little genetic d. their environment has changed very diversity. little.

In your textbook, read about crustaceans, centipedes, and millipedes.

Determine if each statement is true or false.

______7. Having compound eyes on movable stalks is an advantage for aquatic crustaceans whose potential predators could attack from almost any direction.

______8. The legs of most crustaceans are unspecialized and used only for walking.

______9. You might be more likely to see pill bugs moving around out in the open on a rainy day than on a sunny one.

______10. Both centipedes and millipedes have book lungs for gas exchange.

In your textbook, read about insects.

Using the choices below, label the diagram of a honeybee.

antennae compound eye legs mandibles spiracles wings Complete the table by checking the correct column for each statement.

Type of Metamorphosis

Description Complete Incomplete

17. Insect begins life as a fertilized egg.

18. Larva hatches from an egg.

19. Nymph repeatedly molts and increases in size.

20. Nymph hatches from an egg.

21. Pupa undergoes changes while encased in cocoon.

22. Adults and young usually eat the same food.

23. Adults are the only sexually mature form.