1. 28.1 Section Objectives – page 741 Relate the structural and behavioral adaptations of arthropods to their ability to live in different habitats. Section Objectives: 28.1 Analyze the adaptations that make arthropods an evolutionarily successful phylum.

2. Section 28.1 Summary – pages 741 - 746 A typical _______ is a segmented, _______ invertebrate animal with________ symmetry, an exoskeleton, and jointed structures called appendages. An _______ is any structure, such as a leg or an antenna, that grows out of the body of an animal.

3. Section 28.1 Summary – pages 741 - 746 Arthropods are the earliest known _________ to exhibit jointed appendages. Joints are advantageous because they allow more flexibility in animals that have hard, rigid __________.

4. Section 28.1 Summary – pages 741 - 746 Joints also allow powerful movements of appendages, and enable an appendage to be used in many different ways.

5. Section 28.1 Summary – pages 741 - 746 The exoskeleton is a hard, thick, outer covering made of ______ and ____ (KI tun).

6. Section 28.1 Summary – pages 741 - 746 In other species, the exoskeleton is made of separate ______ held together by hinges. In some species, the exoskeleton is a continuous covering over most of the body.

7. Section 28.1 Summary – pages 741 - 746 In many aquatic species, the exoskeletons are reinforced with ________ ____. The exoskeleton protects and supports internal tissues and provides places for attachment of _______.

8. Section 28.1 Summary – pages 741 - 746 First, they are relatively _____ structures. The larger an arthropod is, the ______ and heavier its exoskeleton must be to support its larger muscles. _________ have their disadvantages.

9. Section 28.1 Summary – pages 741 - 746 A second and more important disadvantage is that exoskeletons cannot _____, so they must be ___ periodically. Shedding the old exoskeleton is called _______.

10. Section 28.1 Summary – pages 741 - 746 When the new ________ is ready, the animal contracts muscles and takes in air or water. This causes the animal’s body to swell until the old exoskeleton splits open, usually along the back.

11. Section 28.1 Summary – pages 741 - 746 Thus, the new exoskeleton hardens in a ________ size, allowing some room for the animal to continue to grow. Before the new exoskeleton hardens, the animal puffs up as a result of increased _______ circulation to all parts of its body.

12. Section 28.1 Summary – pages 741 - 746 When the new exoskeleton is soft, arthropods cannot _____ themselves from danger because they move by bracing muscles against the _____ exoskeleton. Most arthropods ____ four to seven times in their lives before they become adults.

13. Section 28.1 Summary – pages 741 - 746 In most groups of arthropods, segments have become fused into three body sections—_____, _____, and ______.

14. Section 28.1 Summary – pages 741 - 746 In other groups, even these segments may be fused. Some __________ have a head and a fused thorax and abdomen.

15. Section 28.1 Summary – pages 741 - 746 In other groups, there is an abdomen and a fused head and thorax called a ________________. Fusion of the body segments is related to movement and protection.

16. Section 28.1 Summary – pages 741 - 746 This large oxygen demand is needed to sustain the high levels of ________ required for rapid movements. ________ have efficient respiratory structures that ensure rapid oxygen delivery to cells.

17. Section 28.1 Summary – pages 741 - 746 Three types of respiratory structures have evolved in arthropods: ____, ___ tubes, and ____ lungs.

18. Section 28.1 Summary – pages 741 - 746 _____ arthropods exchange gases through _____, which extract oxygen from water and release carbon dioxide into the water.

19. Section 28.1 Summary – pages 741 - 746 Land arthropods have either a system of ______ tubes or _____ lungs.

20. Section 28.1 Summary – pages 741 - 746 Most insects have _______ tubes, branching networks of hollow air passages that carry air throughout the body.

21. Section 28.1 Summary – pages 741 - 746 Air enters and leaves the tracheal tubes through openings on the thorax and abdomen called _______. Muscle activity helps pump the air through the ______ tubes.

22. Section 28.1 Summary – pages 741 - 746 Most _____ and their relatives have book lungs, air-filled chambers that contain leaflike plates.

23. Section 28.1 Summary – pages 741 - 746 The stacked plates of a ____ lung are arranged like pages of a book.

24. Section 28.1 Summary – pages 741 - 746 Movement, sound, and chemicals can be detected with great sensitivity by ______, stalk-like structures that detect changes in the environment.

25. Section 28.1 Summary – pages 741 - 746 Antennae are also used for ____ and ____ communication among animals.

26. The ants were able to work together as a group because they were communicating with each other by ______, chemical odor signals given off by animals. Section 28.1 Summary – pages 741 - 746 Have you ever watched as a group of ants carried home a small piece of food?

27. Section 28.1 Summary – pages 741 - 746 Accurate vision is also important to the active lives of arthropods. Most arthropods have one pair of large _________eyes and three to eight ______ eyes. A simple eye is a visual structure with only one ____ that is used for detecting light. _________ sense the odors of pheromones.

28. Section 28.1 Summary – pages 741 - 746 A ________ eye is a visual structure with many lenses.

29. Section 28.1 Summary – pages 741 - 746 Each lens registers light from a tiny portion of the field of view. The total image that is formed is made up of thousands of parts.

30. Section 28.1 Summary – pages 741 - 746 The nervous system consists of a double _______ nerve cord, an _____ brain, and several ______. Arthropods have ganglia that have become fused. These ganglia act as control centers for the body section in which they are located.

31. Section 28.1 Summary – pages 741 - 746 Arthropod blood is pumped by a heart in an _____ circulatory system with vessels that carry blood away from the heart. The blood flows out of the ______, bathes the tissues of the body, and returns to the heart through open body spaces.

32. Section 28.1 Summary – pages 741 - 746 Arthropods have a complete _______ system with a mouth, stomach, intestine, and anus, together with various glands that produce digestive ________. The mouthparts of most arthropod groups include one pair of jaws called ___________.

33. Section 28.1 Summary – pages 741 - 746 The mandibles, together with other mouthparts are adapted for holding, chewing, sucking, or biting the various foods eaten by arthropods.

34. Section 28.1 Summary – pages 741 - 746 Most ______ arthropods excrete wastes through _______ tubules. In insects, the tubules are all located in the _______ rather than in each segment. Malpighian tubules are attached to and empty into the _______.

35. Section 28.1 Summary – pages 741 - 746 Another well-developed system in arthropods is the ______ system. In an arthropod limb, the muscles are attached to the inner surface of the ___________. An arthropod muscle is attached to the exoskeleton on both sides of the joint.

36. Section 28.1 Summary – pages 741 - 746 Most arthropod species have separate males and females and reproduce _______. Fertilization is usually _______ in land species but is often _______ in aquatic species.

37. Section 28.1 Summary – pages 741 - 746 Some species, including bees, ants, aphids, and wasps, exhibit ______________, a form of asexual reproduction in which a new individual develops from an unfertilized egg.

38. 28.2 Section Objectives – page 747 Compare and contrast the similarities and differences among the major groups of arthropods. Section Objectives: 28.2 Explain the adaptations of insects that contribute to their success.

39. Section 28.2 Summary – pages 747 - 755 ___ and ____ differ from spiders in that they have only one body section. tick

40. Section 28.2 Summary – pages 747 - 755 The head, thorax, and abdomen are completely fused. Ticks feed on ____ from reptiles, birds, and mammals.

41. Section 28.2 Summary – pages 747 - 755 ___ feed on fungi, plants, and animals. They are so small that they often are not visible to the unaided human eye. Like ticks, mites can transmit ______.

42. Section 28.2 Summary – pages 747 - 755 _______ are easily recognized by their many abdominal body segments and enlarged ________. They have a long tail with a _______ stinger at the tip.

43. Section 28.2 Summary – pages 747 - 755 ______ (krus TAY shuns) are the only arthropods that have two pairs of antennae for sensing. All crustaceans have ________ for crushing food and typically have two compound eyes.

44. Section 28.2 Summary – pages 747 - 755 Unlike the up-and-down movement of your jaws, crustacean mandibles open and close from ____ to _____. Many crustaceans have ____ pairs of walking legs.

45. Section 28.2 Summary – pages 747 - 755 The first pair of walking legs are often modified into strong ______ for defense. claw legs

46. Section 28.2 Summary – pages 747 - 755 Members of the class _______ include crabs, lobsters, shrimps, crayfishes, water fleas, pill bugs, and barnacles.

47. Section 28.2 Summary – pages 747 - 755 Most crustaceans are _____ and exchange gases as water flows over feathery ____. __ bugs and ___bugs, two of the few land crustaceans, must live where there is _______, which aids in gas exchange.

48. Section 28.2 Summary – pages 747 - 755 Like spiders, ______ and ______ have Malpighian tubules for excreting wastes. In contrast to spiders, centipedes and millipedes have _______ tubes rather than book lungs for gas exchange.

49. Section 28.2 Summary – pages 747 - 755 Centipedes are ___________ and eat soil arthropods, snails, slugs, and worms The ____ of some centipedes are painful to humans.

50. Section 28.2 Summary – pages 747 - 755 A millipede eats mostly plants and dead material on damp forest floors. _______ do not bite, but they can spray foul-smelling fluids from their defensive _____ glands.

51. Section 28.2 Summary – pages 747 - 755 __________ crabs are members of the class __________. Horshoe crabs are considered to be living fossils; Limulus fossils have remained relatively unchanged since the ______ Period about 220 million years ago.

52. Section 28.2 Summary – pages 747 - 755 Horseshoe crabs are heavily protected by an extensive __________ and live in deep coastal waters. They forage on sandy or muddy ocean bottoms for algae, _______, and mollusks.

53. Section 28.2 Summary – pages 747 - 755 Flies, grasshoppers, lice, butterflies, bees, and beetles are just a few members of the class _______. Insects have ____ body segments and ___ legs. There are more ______ of insects than all other classes of animals combined.

54. Section 28.2 Summary – pages 747 - 755 Insects usually mate _____ during their lifetime. The eggs usually are ______ internally. Some insects exhibit ___________, reproducing from unfertilized eggs.

55. Section 28.2 Summary – pages 747 - 755 Most insects lay a ____ number of eggs, which increase the chances that some offspring will survive long enough to reproduce.

56. Section 28.2 Summary – pages 747 - 755 After eggs are laid, the insect _______ develops and the eggs hatch. In some _______ insects development is direct; the eggs hatch into miniature forms that look just like tiny adults.

57. Section 28.2 Summary – pages 747 - 755 These insects go through successive ___ until the adult size is reached. Eggs Nymph Molt Nymph Molt Adult

58. Section 28.2 Summary – pages 747 - 755 In some cases, the adult insect bears little resemblance to its ________ stage. Adult Egg Larva Pupa

59. Section 28.2 Summary – pages 747 - 755 Insects that undergo metamorphosis usually go through four stages on their way to adulthood: ___, _____, ____, and ______. This series of changes, controlled by chemical-substances in the animal, is called _______________.

60. Section 28.2 Summary – pages 747 - 755 Other insects that undergo complete metamorphosis include ants, beetles, flies, and wasps.

61. Section 28.2 Summary – pages 747 - 755 Many insect species, as well as other arthropods, undergo a gradual or incomplete metamorphosis, in which the insect goes through only _____ stages of development. These three stages are ___, ______, and adult.

62. Section 28.2 Summary – pages 747 - 755 A _____, which hatches from an egg, has the same general appearance as the adult but is smaller. Eggs Nymph Molt Nymph Molt Adult

63. Section 28.2 Summary – pages 747 - 755 ________ cannot reproduce. As the nymph eats and grows, it molts several times. With each _____, it begins to resemble the adult more. Gradually, the nymph becomes an adult.

64. Section 28.2 Summary – pages 747 - 755 Grasshoppers and cockroaches are insects that undergo ________ metamorphosis. Incomplete metamorphosis of a harlequin bug

65. Section 28.2 Summary – pages 747 - 755 The success of arthropods can be attributed in part to their varied life cycles, high reproductive output, and structural adaptations, such as small size, a hard exoskeleton, and jointed appendages.

66. Section 28.2 Summary – pages 747 - 755 Arthropods most likely evolved from an ancestor of the _______.

67. Section 28.2 Summary – pages 747 - 755 Segments in arthropods are more complex than in annelids, and arthropods have more developed _____ tissue and sensory organs, such as eyes.

68. Section 28.2 Summary – pages 747 - 755 The exoskeleton of arthropods provides _______ for their soft bodies.

69. Section 28.2 Summary – pages 747 - 755 Muscles in arthropods are arranged in _____ associated with particular segments and portions of appendages. The circular muscles of _______ do not exist in arthropods. Because arthropods have many hard parts, much is known about their evolutionary history.