Chapter 29: Echinoderms and Invertebrate Chordates

Echinoderms and Chapter 29 Organizer Invertebrate Chordates

Refer to pages 4T-5T of the Teacher Guide for an explanation of the National Science Education Standards correlations. Teacher Classroom Resources Activities/FeaturesObjectivesSection MastersSection TransparenciesReproducible

Reinforcement and Study Guide, pp. 127-129 L2 Section Focus Transparency 71 L1 ELL Section 29.1 1. Compare similarities and differences MiniLab 29-1: Examining Pedicellariae, p. 788 Section 29.1 among the classes of echinoderms. Inside Story: A Sea Star, p. 790 Critical Thinking/Problem Solving, p. 29 L3 Basic Concepts Transparency 50 L2 ELL Echinoderms 2. Interpret the evidence biologists have Problem-Solving Lab 29-1, p. 792 Echinoderms BioLab and MiniLab Worksheets, p. 129 L2 Basic Concepts Transparency 51 L2 ELL National Science Education for determining that echinoderms are Investigate BioLab: Observing Sea Urchin Laboratory Manual, pp. 205-210 L2 P Standards UCP.1-5; A.1, A.2; close relatives of chordates. Gametes and Egg Development, p. 800 Content Mastery, pp. 141-142, 144 L1 P 1 Physics Connection: Hydraulics of Sea Stars, C.3, C.5, C.6 (1 session, /2 P block) p. 802 P Reinforcement and Study Guide, p. 130 L2 P Section Focus Transparency 72 L1 ELL Section 29.2 LS Concept Mapping, p. 29 L3 ELL Reteaching Skills Transparency 43PL1 ELL P LS Invertebrate Critical Thinking/Problem Solving, p. 29 L3P P Chordates LS Section 29.2 3. Summarize the characteristics of MiniLab 29-2: Examining a Lancelet, p. 797 BioLab and MiniLab Worksheets, pp.P 130-132LS LSL2 P chordates. Inside Story: A Tunicate, p. 798 Content Mastery, pp. 141, 143-144P L1 P Invertebrate 4. Explain how invertebrate chordates Problem-Solving Lab 29-2, p. 799 LSLS Chordates are related to vertebrates. P P LS LS Assessment Resources AdditionalP Resources National Science Education 5. Distinguish between sea squirts LS P LS Standards UCP.1, UCP.2, and lancelets. Chapter Assessment, pp. 169-174 LS Spanish Resources ELL P LS UCP. 4, UCP.5; A.1, A.2; MindJogger Videoquizzes English/Spanish Audiocassettes ELL P C.3, C.5, C.6; G.1-3 (2 ses- LS LS P 1 PerformanceAssessment Assessment Resources in the Biology Classroom AdditionalCooperativeLS Learning Resources in the Science Classroom COOP LEARN sions, /2 block) LS Alternate Assessment in the Science Classroom Lesson Plans/Block SchedulingP LS Computer Test Bank P P LS BDOL Interactive CD-ROM, Chapter 29 quiz LS Need Materials? Contact Carolina Biological Supply Company at 1-800-334-5551 KeyKey toto TeachingTeaching StrategiesStrategies or at http://www.carolina.com LS L1 Level 1 activities should be appropriate LS MATERIALS LIST for students with learning difficulties. LS LS L2 Level 2 activities should be within the BioLab Alternative Lab ability range of all students. Teacher’s p. 800 microscope, microscope slides (5), p. 796 microscope, prepared slides of L3 Level 3 activities are designed for above- coverslips (5), petri dish, dropper (2), sea urchin development and lancelets average students. Corner The following multimedia resources are available from Glencoe. test tube, beaker (2), sea water, live sea ELL ELL activities should be within the ability Quick Demos Products Available From Index to National urchins (male and female), syringe with range of English Language Learners. Biology: The Dynamics of Life p. 789 stereomicroscope, live sea Glencoe Geographic Magazine needle, potassium chloride solution COOP LEARN Cooperative Learning activities CD-ROM ELL urchin, toothpick To order the following products, The following articles may be P are designed for small group work. Exploration: The Five Kingdoms MiniLabs p. 789 dropper P call Glencoe at 1-800-334-7344: used for research relating to this P These strategies represent student prod- Exploration: Echinoderms p. 788 microscope, prepared slide of p. 791 heavy book P CD-ROM chapter: ucts that can be placed into a best-work Exploration: Symmetry sea star pedicellariae, paper, pencil p. 795 preserved specimens of tuni- P NGS PictureShow: Structure of “Pillar of Life,” by George Grall, P portfolio. BioQuest: BiodiversityP Park p. 797 stereomicroscope, microscope cates and lancelets Invertebrates July 1992. LS These strategies are useful in a block Videodisc Program slide, forceps, metric ruler, preserved p. 796 microscope, prepared slide of LS scheduling format. Transparency Set specimen of Branchiostoma cali- lancelet cross section LS NGS PicturePack: Structure of Starfishes forniense (Amphioxus) LS Invertebrates LS LS The Secret of Life Series Sea Stars Chordate Body Plan Action of Tube Feet

786A 786B ChapterChapter 2929 ChapterChapter SECTION PREVIEW Section Objectives Section 29.1 Compare similarities Echinoderms and and differences among 29.1 Echinoderms the classes of echino- GETTING STARTED DEMO 29 derms. Prepare Invertebrate Chordates Interpret the evidence Visual-Spatial Use live biologists have for Key Concepts or preserved sea stars or determining that hink about what the best defense echinoderms are close The characteristics common to sea urchins to point out the What You’ll Learn relatives of chordates. might be for a small animal that echinoderms are presented. The physical characteristics of You will compare and moves slowly in tide pools on the Vocabulary diversity of echinoderms is con- contrast the adaptations T ray echinoderms. Elicit from stu- of echinoderms. seashore. Did you think of armor, spines, or sidered. Deuterostome develop- dents how the meaning of the pedicellaria You will distinguish the fea- perhaps poison as methods of protection? tube feet ment is examined in terms of its term echinoderm relates to tures of chordates by examin- Sea urchins are masters of defense—some ampulla evolutionary significance. the features of animals in this ing invertebrate chordates. water vascular system use all three methods. The sea urchin looks madreporite group. Echinoderm means different from the feather star and from “spiny skin.” The animals clas- Why It’s Important Planning the sea star on the facing page, yet sified in this phylum have By studying how echinoderms Obtain droppers for the Quick and invertebrate chordates all three belong to the same phy- P Demos. spinelike structures covering function, you will enhance your lum. What characteristics do Make photocopies of the their bodies. understanding of evolutionary they have in common? What relationships between these Feather star inner, shaded area of Figure two groups. features determine whether an animal is an echinoderm? (above) and sea 29.6 for the Reteach. LS urchin (inset) Theme Development GETTING STARTED Evolution is a major theme in this chapter. Students study how Observing a Sand Dollar 1 Focus Examine the brittle skeleton of echinoderm larvae and inverte- a sand dollar. Notice the petal- Bellringer brate chordates show similarities like marking on its upper sur- starfishes, may not appear spiny at to certain vertebrates. The theme face. What kind of symmetry What Is an Echinoderm? Before presenting the lesson, first glance, but a close look reveals of systems and interactions is does this organism exhibit? Members of the phylum Echino- display Section Focus Trans- that their long, tapering arms, called WORD Origin obvious as students learn how the dermata have a number of unusual parency 71 on the overhead pro- To find out rays, are covered with short, rounded characteristics that easily distinguish echinoderm jector and have students answer echinoderms and invertebrate more about spines. The spiny skin of a sea From the Greek them from members of any other the accompanying questions. chordates are adapted to and echinoderms and invertebrate cucumber consists of soft tissue words echinos, chordates, visit the Glencoe animal phylum. Echinoderms move interact with their environments. embedded with small, platelike struc- meaning “spiny,” L1 ELL Science Web Site. by means of hundreds of hydraulic, and derma, meaning www.glencoe.com/sec/science suction cup-tipped appendages and tures that barely resemble spines. “skin.” Echinoderms have skin covered with tiny, jawlike The endoskeleton of all echinoderms are spiny-skinned

is made primarily of calcium carbon- ECTION OCUS animals. TransparencyP 71 Echinoderms S F pincers. Echinoderms (ih KI nuh Use with Chapter 29, Section 29.1 If time does not permit teach- durmz) are found in all the oceans of ate, the compound that makes up pedicellariae ing the entire chapter, use the the world. limestone. From the Latin Some of the spines found on sea BioDigest at the end of the word pediculus, A sea star extends its stom- Echinoderms have endoskeletons stars and sea urchins have become meaning “little unit as an overview. foot.” Pedicellariae LS ach from its mouth and If you were to examine the skin of modified into pincerlike appendages Brittle star resemble little feet. engulfs a sea urchin. Hours several different echinoderms, you called pedicellariae (PED ih sihl AHR P later, the sea star draws would find that they all have a hard, ee ay). An echinoderm uses its jawlike its stomach back in and spiny, or bumpy endoskeleton cov- pedicellariae for protection and for moves away. All that’s left of the urchin is the bumpy ered by a thin epidermis. The long, cleaning the surface of its body. You globe you see here. Even its pointed spines on a sea urchin are can examine these structures in the LS Sea urchin

spines are gone. obvious. Sea stars, sometimes called MiniLab on the following page. Sand dollar

1 The word echinoderm comes from the Greek echinos, 786 29.1 ECHINODERMS 787 meaning “spiny,” and derm, meaning “skin.” Why do you think this name was given to this group of organisms? Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

2 How is the radial symmetry of these saltwater animals an advantage?

AssessmentAssessment PlannerPlanner BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES Look for the following logos for strategies that emphasize different learning modalities. Portfolio Assessment Assessment, TWE, pp. 793, 799 Multiple Kinesthetic Meeting Individual Linguistic Biology Journal, MiniLab, TWE, pp. 788, 797 Problem-Solving Lab, TWE, p. 798 Learning Needs, p. 788; Quick Demo, p. 790 Assessment, TWE, p. 789 Knowledge Assessment pp. 789, 791; Activity, p. 795 Naturalist Portfolio, p. 792; Problem-Solving Lab, TWE, p. 792 Section Assessment, SE, pp. 793, 799 ResourceResource Styles Visual-Spatial Quick Demo, Check for Understanding, Portfolio, TWE, p. 792 Chapter Assessment, SE, pp. 803-805 ManagerManager pp. 789, 796; Tech Prep, p. 789; p. 793; Reteach, p. 793; Quick Demo, Performance Assessment Assessment, TWE, p. 796 Section Focus Transparency 71 Project, p. 790; Portfolio, p. 795; p. 795 BioLab, SE, pp. 800-801 BioLab, TWE, pp. 800-801 and Master L1 ELL Reteach, p. 799 MiniLab, SE, pp. 788, 797 Skill Assessment Alternative Lab, TWE, pp. 796-797 Alternative Lab, TWE, pp. 796-797 786 787 P

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LS other aspects of their environment Connection at the end of this chapter. Quick Demo 2 Teach Observing 3 from all directions. Observe the radial The water vascular system is a MiniLab 29-1 and Inferring Magnification: 22 symmetry, as well as the various sizes hydraulic system that operates under Visual-Spatial Have stu- and shapes of spines, of each echino- water pressure. Water enters and dents observe the pedicel- MiniLab 29-1 Examining Pedicellariae Echinoderms P move by tube feet. They also have tiny derm pictured in Figure 29.1. leaves the water vascular system of a lariae of a live sea urchin under pincers on their skin called pedicellariae. sea star through the madreporite a stereomicroscope and make Purpose The water vascular system (MAH dray pohr ite), a sievelike, disk- sketches of their observations. Students will observe the pin- Procedure Another characteristic unique to shaped opening on the upper surface Have them touch one pedicel- cherlike structure of pedicellar- ! Observe a slide of sea star pedicellar- LS echinoderms is the water vascular sys- of the echinoderm’s body. You can laria with a toothpick to iae. iae under low-power magnification. tem that enables them to move, think of this disk as being like the lit- P CAUTION: Use caution when work- observe the structure’s Pedicellariae exchange gases, capture food, and tle strainer that fits into the drain in a Process Skills ing with a microscope and slides. response. L2 ELL @ Record the general appearance of one pedicellaria. What excrete wastes. Look at the close-up sink and keeps large particles out of observe and infer, compare and of the underside of a sea star in the pipes. You can find out how a sea contrast, draw a conclusion, mea- does it look like? # Make a diagram of one pedicellaria under low-power Figure 29.2. You can see that grooves star eliminates wastes by reading the LS sure in SI magnification. filled with tube feet run from the area Inside Story on the next page. sists of long, tapering rays that Figure 29.2 P Teaching Strategies $ Record the size of one pedicellaria in micrometers. of the sea star’s mouth to the tip of Finally, tube feet function in gas extend from the animal’s central disk. Tube feet enable sea Quick Demo each ray. Tube feet are hollow, thin- exchange and excretion. Gases are At the tip of each ray, on the under- stars and other echin- Review the procedure for mea- Analysis oderms to creep walled tubes that end in a suction cup. exchanged and wastes are eliminated side, is an eyespot, a sensory organ Kinesthetic Provide suring objects under the micro- 1. Describe the general appearance of one pedicellaria. along the ocean bot- each studentP with a Tube feet look somewhat like minia- by diffusion through the thin walls of consisting of a cluster of light-detect- tom or to pry open scope. 2. What is the function of this structure? dropper. Have themLS squeeze ture droppers. The round, muscular the tube feet. ing cells. When walking, sea stars the shells of bivalves. Prepared slides are available 3. Explain how the structure of pedicellariae assists in their the air from the dropper, and function. structure called the ampulla (AM puh curve up the tips of their rays so that from biological supply houses. lah) works something like the bulb of Echinoderms have varied nutrition the eyespots are turned up and out- then, while still applying pres- Expected Results a dropper. The end of a tube foot All echinoderms have a mouth, ward. This enables a sea star to de- sure to the LSrubber end of the Students will observe that pedi- works like a tiny suction cup. Each stomach, and intestines, but their tect the intensity of light coming from dropper, touch the dropper Echinoderms have radial symmetry cellariae have a pincherlike tube foot works independently of the methods of obtaining food vary. Sea every direction. tip to their finger. They should You may remember that radial sym- others, and the animal moves along stars are carnivorous and prey on release the pressure on the appearance and measure close to Echinoderms have bilaterally metry is an advantage to animals that slowly by alternately pushing out and worms or on mollusks such as clams. dropper and observe how the 250µm in length. symmetrical larvae are stationary or move slowly. Radial pulling in its tube feet. You can learn Most sea urchins are herbivores and Figure 29.3 dropper holds to their finger. Analysis symmetry enables these animals to more about the operation of the graze on algae. Brittle stars, sea lilies, If you examine the larval stages of These sea urchin lar- Explain that this is similar to vae are only 1 mm in 1. Student answers will vary— sense potential food, predators, and water vascular system in the Physics and sea cucumbers feed on dead and echinoderms, you will find that they the suction action of the tube pincherlike, plierslike, for- decaying matter that drifts down to have bilateral symmetry, a feature size. The larval stage P of echinoderms is feet of a sea star. L2 ELL cepslike Figure 29.1 the ocean floor. Sea lilies capture this more common to chordates. The cil- bilateral, even 2. allows animal to grasp All echinoderms have radial symmetry suspended organic matter with their iated larva that develops from the though the adult objects, clean itself of debris, as adults and an endoskeleton com- C A sea lily’s feathery tentaclelike tube feet and move it to fertilized egg of an echinoderm is stage has radial posed primarily of calcium carbonate. protection rays are composed their mouths. shown in Figure 29.3. Through symmetry. LS P of calcified skeletal 3. These pincherlike organs metamorphosis, the free- A A brittle star’s long, snakelike plates covered with Echinoderms have a simple swimming larvae make Assessment allow the sea star to pinch an epidermis. rays are composed of overlap- nervous system dramatic changes in both potential predators when Portfolio Ask students to ping, calcified plates covered Echinoderms have no head or body parts and in symmetry. P with a thin layer of skin cells. make a table showing theLS differ- they touch the animal. Their brain, but they do have a central The bilateral symmetry of shape also allows the sea star ent groups of echinoderms, the nerve ring that surrounds the mouth. echinoderm larvae indicates type of food they eat, and to clean itself by picking off Nerves extend from the nerve ring that echinoderm ancestors materials that become stuck whether or not they move around B A living sand dollar down each ray. Each radial nerve also may have had bilateral to find their food. LSAsk them to to its body. has a solid, immov- then branches into a nerve net that symmetry, suggesting a relate the type of food to the ani- able skeleton com- provides sensory information to the close relationship to the posed of flattened animal. Echinoderms have cells that chordates. You can observe mals’ methods of locomotion. plates that are fused Have them include their table and Assessment together. detect light and touch, but most do sea urchin development in Portfolio Have students not have sensory organs. Sea stars are the BioLab at the end of explanation in their portfolios. write a lab report that summarizes an exception. A sea star’s body con- this chapter. L2 P their results and place it in their portfolios. Use the Performance 788 29.1 ECHINODERMS 789 Task Assessment List for Lab ResourceResource Report in PASC, p. 47. L2 LS ManagerManager P MEETING INDIVIDUAL NEEDS BioLab and MiniLab Work- Visual Learning Visually Impaired P sheets, p. 129 L2 Have students examine the ani- CD-ROM Kinesthetic Provide visually Raising Sea Stars added to the tank. Ask them to interview mals shown in Figure 29.1LS Biology: The Dynamics of Life impaired students with dried speci- Visual-Spatial Ask students to visit a the person in charge of taking care of the closely. Challenge them to iden- Exploration: The Five Kingdoms mens of various echinoderms. Allow stu- saltwater aquarium at a local zoo or aquarium to find out what daily tasks the tify the lines of symmetry for Disc 3 P dents to handle the specimens so they can pet shop. Have them visit when the sea stars caretaker must perform to maintain the sea LS each organism that has radial P feel the shapes, sizes, and characteristic and sea urchins are being fed. Ask students stars and sea urchins. Have students report symmetry. L1 P spiny skins of these animals. L1 ELL to observe and record sea star feeding their findings to the class. L2 P behavior when live clams or oysters are COOP LEARN 788 LS 789 P LS LS P LS

LS LS P P P

LS LS LS NSIDENSIDE NSIDENSIDE Diversity of with spines, as Figure 29.4 shows. Quick Demo II II Echinoderms They do not have rays. The circular, TORY flat skeletons of sand dollars have a Kinesthetic When a sea S STORY Approximately 6000 species of five-petaled flower pattern on the P star tries to open a clam echinoderms exist today. More than surface. A living sand dollar is cov- or oyster, its muscles must Purpose A Sea Star one-third of these species are in the ered with minute, hairlike spines that overcome the force exerted by Students will learn about the class Asteroidea (AS tuh royd ee uh), to are lost when the animal dies. A sand mollusk muscles that are try- which the sea stars belong. The four structural and behavioral adapta- f you ever tried to pull a sea star from a rock where it is dollar has tube feet that protrude ing to keep the shells closed. LS other classes of living echinoderms tions of a sea star. Iattached, you would be impressed by how unyielding and from the petal-like markings on its A sea star opens a bivalve by are Ophiuroidea (OH fee uh royd ee rigid the animal seems to be. Yet at other times, the animal upper surface. These tube feet are applying a steady, unrelenting uh), the brittle stars; Echinoidea (eh modified into gills. Tube feet on the Teaching Strategies shows great flexibility, such as when it rights itself after being pressure until the bivalve’s kihn OYD ee uh), the sea urchins and animal’s bottom surface aid in bring- Ask students to observe a live turned upside down. muscles tire. Tell students to sand dollars; Holothuroidea (HOH ing food particles to the mouth. sea star in action. They can use a hold their arms straight out to Critical Thinking How is radial symmetry useful to a sea star? Blood sea star loh thuh royd ee uh), the sea cucum- Sea urchins look like living pin- hand lens to observe the tube feet bers; and Crinoidea (cry NOYD ee cushions, bristling with long, usually the side with their palms up. as the sea star “walks” or “climbs” uh), the sea lilies and feather stars. Their arm muscles represent a surface of a marine aquarium. 1 Endoskeleton A sea star can maintain a the bivalve’s muscles. Have a L1 ELL rigid structure or be flexible because it has 8 Pedicellariae The pincerlike Sea stars Figure 29.4 partner place a heavy book on an endoskeleton in the form of calcium pedicellariae on the rays of the Echinoderms are Most species of sea stars have five the students’ open palms. Ask Visual Learning carbonate plates just under its epidermis. sea star will pinch any animal adapted to life in a The plates are connected by bands of that tries to crawl over it. rays, but some have more. Some variety of habitats. them to time how long they Make photocopies of the soft tissue and muscle. When the P species may have more than 40 rays. can hold their arms out before Inside Story diagram without muscles are contracted, the body The rays are tapered and extend from A Basket stars, a dropping the book. The book the labels of the structures. becomes firm and rigid. When the central disk. You have already P the muscles are relaxed, the kind of brittle star, represents the sea star’s mus- read about the characteristics of sea Number the parts and explain body becomes flexible. live on the soft cles. L2 ELL to students how each part Pedicellaria Ray stars that make them a typical exam- substrate found functionsLS and how the parts ple of echinoderms. below deep ocean 2 Madreporite Water flows waters. Penable the sea star to survive in 2 LS in and out of the water Brittle stars P its environment. Have stu- vascular system through 7 Anus Waste As their name implies, brittle stars dents use this information to the madreporite. products of diges- are extremely fragile, Figure 29.4. If label the diagram. L1 tion are eliminated Ring you try to pick up a brittle star, parts LS Nerve through the anus. B Sea urchins often P Radial canal of its rays will break off in your hand. VIDEODISC Critical Thinking ring burrow into LS canal This is an adaptation that helps the rocks to protect The Secret of Life Radial symmetry enables animals brittle star survive an attack by a themselves Sea Stars that move slowly to sense and 6 Stomach To eat, a sea predator. While the predator is busy from preda- obtain potential food, escape star pushes its stomach with the broken-off ray, the brittle tors and !7;F8C"LS predators, and sense other Radial out of its mouth and rough Ampula Mouth star can escape. A new ray will regen- nerve spreads the stomach water. Biology: The Dynamics of Life aspects of their environment erate within weeks. over the food. Powerful Starfishes (Ch. 39) from all directions. enzymes secreted by the Brittle stars do not use their tube Tube feet The suction P 3 Reproductive digestive gland turn solid Disc 1, Side 2, 49 sec. action of tube feet, feet for locomotion. Instead, they organ food into a soupy liquid caused by the contraction propel themselves with the snakelike, that the stomach can and relaxation of the slithering motion of their flexible C Sand dollars bur- !:áÄ" easily absorb. Then the ampulla, is so strong row into the sandy sea star pulls the stom- rays. They use their tube feet to pass LS that the sea star’s particles of food along the rays and ocean bottom. ach back into its body. They feed on tiny CD-ROM muscles can open a into the mouth in the central disk. clam or oyster shell. Endoskeletal organic particles Biology: The Dynamics found in the sand. plates Sea urchins and sand dollars ResourceResource of Life 5 Digestive gland The ManagerManager Exploration: Echinoderms 4 Eyespots When moving, a sea star curves digestive gland gives off Sea urchins and sand dollars are up the tips of its rays so that the eyespots chemicals for digestion. globe- or disk-shaped animals covered Disc 4 are turned up and outward. Echinoderm Laboratory Manual, Exploration: Symmetry eyespots distinguish between light and pp. 205-210 L2 Disc 4 790 dark but do not form images. 29.1 ECHINODERMS 791 Critical Thinking/Problem Solving, p. 29 L3 Basic Concepts Transparency PROJECT BIOLOGYIOLOGY JOURNAL Cultural Diversity 50 and Master L2 ELL Japan and the Sea Urchin Industry Echinoderm Display Sea Star Life pest to commercial fisheries. Visual-Spatial Ask a group of stu- in Maine Sea urchins are prized in Japan as uni, a Linguistic Have students write an P P dents to create a bulletin board dis- Introduce students to what is rapidly becom- sushi delicacy. The Japanese value the sea P essay in which they describe one day play of echinoderms. Have them highlight ing a $100 million international industry— urchin for the quality of its eggs, called roe. in the life of a sea star. Allow a few stu- the features of echinoderms. Ask them the importation of Maine sea urchins to Today more than 95% of all sea urchins har- dents to read their essays. Have other stu- to find examples of everyday objects that Japan. Once a remote destination in winter, vested in Maine are sent to Japan. The har- dents discuss which parts of the essays LS P show similar traits. Students may use sand- P coastal Maine has become a magnet for vesting of sea urchins is also becoming big LS LS P were scientific and which were creative paper to model the texture of echinoderm Japanese businesspeople because of the sea business in California. fiction. L3 790 skin. L2 ELL COOP LEARN urchin, a creature once considered to be a 791

P LS LS LS P P LS P LS LS LS Problem-Solving Lab 29-1 pointed spines. They have long, slen- Figure 29.6 Designing an der tube feet that, along with the Most echinoderms have been found 3 Assess P Problem-Solving Lab 29-1 Experiment spines, aid the animal in locomotion. as fossils from the early Paleozoic Holothuroids era. Fossils of brittle stars 1500 species Purpose The sea urchin’s spines protect it Check for Understanding What makes sea cucumbers are found beginning at a Students will design an experi- release gametes? The orange from predators. In some species, sacs later period. Naturalist Ask students to ment to determineLS the stimulus sea cucumber lives in groups of located near the tips of the spines use Figure 29.6 to explain for release of sea cucumber 100 or more per square meter. contain a poisonous fluid that is the phylogenetic history of In the spring, these sea cucum- injected into an attacker, further pro- Asteroids gametes. 1500 species echinoderms. L2 bers produce large numbers of tecting the urchin. The spines also ANIMALS gametes (eggs and sperm), which aid in locomotion and in burrowing. Process Skills they shed in the water all at the Ophiuroids Reteach Orange sea cucumber Burrowing species move their spines 2000 species Echinoids design an experiment, identify same time. The adaptive value of 950 species Naturalist Give students and control variables such behavior is that fertilization of many eggs is assured. in a circular motion that grinds away When one male releases sperm, the other sea cucumbers in the rock beneath them. This action, photocopies of the inner, Teaching Strategies the population, both male and female, also release their which is aided by a chewing action of shaded part of the phylogenetic gametes. Biologists do not know whether the sea cucumbers the mouth, forms a depression in the diagram in Figure 29.6. Have Ask students to think of strate- release their gametes in response to a seasonal cue, such as P rock that helps protect the urchin them place each class in its cor- gies that animals may use to increasing day length or increasing water temperature, or from predators and from wave action rect position. Ask them to list ensure aquatic fertilization. Likely whether they do this in response to the release of sperm by one sea cucumber. that could wash it out to sea. also the identifying features of answers will include releasing large Crinoids 600 species each class. L1 numbers of eggs and sperm, and Analysis Sea cucumbers LS releasing eggs and sperm at the same Design an experiment that will help to determine Sea cucumbers are so called because PRECAMBRIANPALEOZOIC MESOZOIC CENOZOIC PRESENT Extension time. whether sea cucumbers release eggs and sperm in response to the release of sperm from one individual or in response to of their vegetablelike appearance, shown in Figure 29.5. Their leathery Have students research and re- a seasonal cue. Recall that most invertebrates show Thinking Critically covering allows them to be more Origins of Echinoderms port on the relationship between Thinking Critically protostome development, whereas To design an experiment, stu- flexible than other echinoderms; they the crown-of-thorns sea star and If you find that female sea cucumbers release 200 eggs in The earliest echinoderms may deuterostome development appears dents may decide to keep a group pull themselves along the ocean floor coral reefs. L3 the presence of male sperm and ten eggs in the presence of have been bilaterally symmetrical as mainly in chordates. The echino- of female sea cucumbers in using tentacles and tube feet. When water that is warmer than the surrounding water, what adults, and probably were attached to derms represent the only major group aquariums, control all environ- would you do in your next experiment? sea cucumbers are threatened, they the ocean floor by stalks. Another of deuterostome invertebrates. P exhibit a curious behavior. They may Assessment mental variables, and then release view of the earliest echinoderms is Because the endoskeletons of expel a tangled, sticky mass of tubes sperm into the water to see if this that they were bilateral and free- echinoderms easily fossilize, there is Performance Have stu- through the anus, or they may rup- causes the release of eggs. swimming. The development of a good record of this phylum. dents prepareP a demonstration for Figure 29.5 a ture, releasing some internal organs bilateral larvae is one piece of evi- Echinoderms, as a group, date from third gradersLS that explains the Sea lilies and feather that are regenerated in a few weeks. dence biologists have for placing the Paleozoic era, as shown in Figure water vascular system of a sea star. stars use their feathery These actions confuse their predators, Assessment echinoderms as the closest inverte- 29.6. More than 13 000 fossil species Ask them to present this demon- rays to capture down- giving the sea cucumber an opportu- Portfolio Explain to stu- ward-drifting organic brate relatives of the chordates. have been identified. stration to theLS class using a work- nity to move away. Sea cucumbers dents that sea stars have been particles (a). Sea ing model. L2 ELL cucumbers trap organic reproduce by shedding eggs and found to spawn on the same day particles by sweeping sperm into the water, where fertiliza- Section Assessment as sea cucumbers. Ask if this indi- their mucous-covered tion occurs. You can find out more Section Assessment cates that the stimulus for spawn- tentacles over the about sea cucumber reproduction in Understanding Main Ideas Thinking Critically P ocean bottom (b). 4 Close ing is environmental or is in the Problem-Solving Lab on this page. 1. How does a sea star move? Explain in terms of 5. How do the various defense mechanisms among response to one male first releas- the water vascular system of echinoderms. the echinoderm classes help deter predators? b Sea lilies and feather stars 2. Describe the differences in symmetry between Activity ing sperm. Ask students to write SKILL REVIEWEVIEW larval echinoderms and adult echinoderms. Show a film Pabout echinoderms their responses in their portfolios. Sea lilies and feather stars resem- 3. How are sea cucumbers different from other 6. Classifying Prepare a key that distinguishes LS Use the Performance Task As- ble plants in some ways. Sea lilies are echinoderms? among classes of echinoderms. Include informa- and their interactions with other sessment List for Making Obser- the only sessile echinoderms. Feather 4. Compare how sea urchins and sea cucumbers tion on features you may find significant. For marine organisms. vations and Inferences in PASC, stars are sessile only in larval form. obtain food. more help, refer to Organizing Information in the Skill Handbook. p. 17. L2 P The adult feather star uses its feath- LS ery arms to swim from place to place.

ResourceResource 792 29.1 ECHINODERMS 793 LS ManagerManager PortfolioPortfolio Content Mastery, p. 142 L1 Section Assessment ReinforcementP and Study Echinoderm Phylogeny 1. A sea star moves by regulation of its plates. free swimming. If an echinoderm such Guide, pp. 127-129 L2 CD-ROM Naturalist Provide students with water vascular system. Tube feet attach 4. Sea urchins graze on algae; sea cucum- as a sea star loses part of a ray, it can Basic Concepts Transparency Biology: The Dynamics of Life echinoderm fossils. Include as many to a surface, the sea star moves itself bers feed on dead matter that drops to be regenerated. Sea cucumbers can 51 and Master L2 ELL BioQuest: Biodiversity Park different kinds as possible and use pho- forward, and the suction is released. the ocean floor. expel their digestive tracts and grow LS Disc 3, 4 tographs of fossils you don’t have. Ask 2. Larval echinoderms are bilaterally sym- 5. The rigid endoskeleton helps protect new ones. students to arrange the fossils and pho- metrical, whereas adult echinoderms echinoderms from their enemies. 6. Students’ keys will vary considerably, P P tographs to illustrate the phylogeny of are radially symmetrical. Spines and poison glands also protect but all should utilize the branching P P this group. L3 P 3. Sea cucumbers are tubular and have a echinoderms. Adult echinoderms move nature of keys described in the Skill 792 leathery outer covering instead of hard by walking, whereas larval forms are Handbook. 793 P LS LS LSLS LS P LS

LS SECTION PREVIEW All chordates have a notochord the body. These movements propel Section 29.2 All chordate embryos have a noto- the animal through the water at a 2 Teach Objectives Section great speed. Summarize the charac- chord (NOHT uh kord)—a long, teristics of chordates. semirigid, rodlike structure located Quick Demo Explain how inverte- 29.2 Invertebrate between the digestive system and the All chordates have a dorsal Prepare brate chordates are dorsal hollow nerve cord. The noto- hollow nerve cord related to vertebrates. Naturalist Ask students Chordates chord is made up of large, fluid-filled The dorsal hollow nerve cord in Key Concepts Distinguish between to observe preserved or cells held within stiff, fibrous tissues. chordates develops from a plate of Students will learn about inverte- sea squirts and lancelets. mounted specimens of tuni- he brightly colored object pictured here In invertebrate chordates, the noto- ectoderm that rolls into a hollow WORD Origin brate chordates. They will distin- Vocabulary cates and lancelets. Ask them is a sea squirt. As one of your closest chord is retained into adulthood. But tube. This occurs at the same time as chordata guish between sea squirts and notochord if they can see any characteris- dorsal hollow Tinvertebrate relatives, it is placed, in vertebrate chordates, this structure the development of the notochord. From the Latin lancelets and study the relation- word chorda, mean- tics that link these animals to nerve cord along with humans, in the phylum Chordata. is replaced by a backbone. Inverte- The sequence of development of the ships of these animals to the ver- gill slit ing “cord.” The vertebrate chordates. Elicit At first glance, this sea squirt may seem to brate chordates do not develop a dorsal hollow nerve cord is illustrated tebrates. phylum Chordata whether the animals might resemble a sponge more than its fellow chor- backbone. in Figure 29.8. This tube is composed consists of animals have unseen characteristics dates. It is sessile, and it filters food The notochord develops just after of cells surrounding a fluid-filled with notochords. P that link them to vertebrate Planning particles from water it takes in the formation of a gastrula from canal that lies above the notochord. Prepare syringes with potas- through the opening at the top mesoderm on what will be the dorsal In most adult chordates, the cells in chordates. L2 sium chloride and gather of its body. What characteris- side of the embryo. The physical sup- the posterior portion of the dorsal port provided by a notochord enables beakers, glass slides, coverslips, tics could a human—or a fish hollow nerve cord develop into the invertebrate chordates to make pow- spinal cord. The cells in the anterior LS and test tubes for the BioLab. or a lizard, for that mat- erful side-to-side movements of portion develop into a brain. A pair Activity ter—share with this colorful, Sea squirt and a Kinesthetic Have students ocean-dwelling organism? human (inset) Figure 29.8 run their fingers along their After gastrulation, organs begin B The dorsal hollow nerve cord C The edges of this plate of backs to feel Ptheir backbones. 1 Focus to form in a chordate embryo. originates as a plate of dorsal ectoderm fold inward, eventu- Explain that the backbone is ectoderm just above the ally meeting to form a hollow unique to vertebrates and forms Bellringer developing notochord. tube surrounded by cells. The Before presenting the lesson, A The notochord forms from dorsal hollow nerve cord from the notochord—the struc- mesoderm on the dorsal side pinches off from the ectoderm ture that identifies all members of display Section Focus Trans- (sea squirts); Cephalochordata, the LS What Is an Invertebrate of a developing embryo. Neural Neural and develops into the central the phylum Chordata. Although parency 72 on the overhead pro- lancelets; and Vertebrata, the verte- fold plate Neural Neural nervous system of the animal. all chordates have a notochord at jector and have students answer Figure 29.7 Chordate? brates. In this section you will exam- fold plate some time during their develop- the accompanying questions. Chordate characteris- The chordates most familiar to you ine the tunicates and lancelets— L1 ELL tics—the notochord, are the vertebrate chordates—chor- invertebrate chordates that have no ment, not all chordates have dorsal hollow nerve dates that have backbones, such as backbones. You will study the verte- backbones. L1 ELL cord, gill slits, and muscle blocks—are birds, fishes, and mammals, including brate chordates in the next unit. Notochord shared by inverte- humans. But the phylum Chordata Invertebrate chordates may not look Ectoderm Visual Learning Invertebrate Chordate TransparencyP 72 SECTION FOCUS DAHT Structures Use with Chapter 29, brate as well as ver- (kor uh) includes three sub- much like fishes, reptiles, or humans, Dorsal hollow Section 29.2 Mesoderm Have students explainP how the tebrate chordates. phyla: Urochordata, the tunicates but like all other chordates, they have Endoderm nerve cord Inside Story on development in a notochord, a dorsal hollow nerve Cells that form Dorsal hollow Dorsal hollow Outer layer Chapter 25 relates to Figure cord, gill slits, and muscle blocks at bones and nerve cord nerve cord Notochord of ectoderm 29.8. LS Dorsal nerve cord some time during their development. muscle Notochord Notochord LS P In addition, all chordates have bilateral symmetry, a well-developed coelom, P Tail Anus Muscle blocks and segmentation. The features shared Mouth Gill Slits by invertebrate and vertebrate chor- Dorsal hollow D Cells migrate from the meeting dates are illustrated in Figure 29.7. nerve cord 1 Which of the structures shown on this animal are not margins of the neural tube and LS 1 Anus Tail VIDEODISC found on other animals you have studied so far? You can observe these features in eventually form other organs, LS 2 What do you think the function of the notochord is? The Secret of Life Mouth Muscle blocks invertebrate chordates in the Problem- including bones and muscles. Gill slits Solving Lab later in this section. Chordate Body Plan Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. !7;FLE" 794 ECHINODERMS AND INVERTEBRATE CHORDATES 29.2 INVERTEBRATE CHORDATES 795

BIOLOGY: The Dynamics of Life SECTION FOCUS TRANSPARENCIES BIOLOGYIOLOGY JOURNAL PortfolioPortfolio Resource Manager Internet Address Book Tunicate Research Note Internet addresses Water Movement in Tunicates Section Focus Transparency 72 and Ask students to use the Internet and their that you find useful in Visual-Spatial Have students use Master L1 ELL local library to do research on tunicates. the space below for quick reference. the diagram in the Inside Story on Concept Mapping, p. 29 L3 ELL Ask them to find out where tunicates live page 798 to make a flowchart that traces Reteaching Skills Transparency 43 and if any tunicate species are threatened the path of water through a sea squirt. P and Master L1P ELL or endangered. Have students place their Have students place their completed flow- P findings in their journals. L2 charts in their portfolios. L2 P

794 P P LS 795 LS P LS LS LS LS P P P LS

LS LS LS of nerves connects the nerve cord to meat to separate easily into flakes. tunic, a tough sac made of cellulose, MiniLab 29-2 Quick Demo P each block of muscles. Muscle blocks are anchored by the around their bodies. Colonies of MiniLab 29-2 Observing Visual-Spatial Have stu- notochord, which gives the muscles a tunicates sometimes secrete just one Purpose All chordates have gill slits firm structure to pull against. As a big tunic that has a common opening dents examine a prepared Examining a Lancelet Branchiostoma Students will observe the external slide of a cross section of a The gill slits of a chordate are result, chordates tend to be more to the outside. You can find out how californiense is a small, sea-dwelling appearanceLS of lancelets. lancelet. Explain that in lance- paired openings located in the phar- muscular than members of other tunicates eat in the Inside Story on the lancelet. At first glance, it appears to be lets the notochord is present ynx, behind the mouth. Many chor- phyla. next page. a fish. However, its structural parts and Process Skills appearance are quite different. throughout the life of the ani- dates have several pairs of gill slits Muscle blocks also aid in move- Only the gill slits in adult tunicates compare and contrast, interpret only during embryonic development. ment of the tail. At some point in indicate their chordate relationship. mal, while in vertebrates the Procedure data, make and use tables, mea- Invertebrate chordates that have gill development, all chordates have a Adult tunicates are small, tubular ani- notochord is replaced by a ! Place the lancelet onto a glass slide. sure in SI, observe and infer slits as adults use these structures to muscular tail. As you know, humans mals that range in size from micro- CAUTION: Wear disposable latex gloves and handle pre- backbone. They should also find strain food from the water. In some are chordates, and during the early scopic to several centimeters long, Teaching Strategies the dorsal hollow nerve cord served material with forceps. vertebrates, especially the fishes, the development of the human embryo, about as big as a large potato. If you @ Use a dissecting microscope to examine the Specimens are available from above the notochord and com- gill slits develop into internal gills there is a muscular tail that disap- remove a tunicate from its sea home, animal. CAUTION: Use care when working with a micro- biological supply houses. pare it with the notochord. Em- that are adapted to exchange gases pears as development continues. In it might squirt out a jet of water for scope and slides. A hand lens may be substituted phasize that the function of the # P during respiration. most animals that have tails, the protection—hence the name sea Prepare a data table that will allow you to record the fol- for a binocular microscope. notochord is to provide support digestive system extends to the tip of squirt. lowing: General body shape, Length in mm, Head region Expected Results for the animal. L2 ELL All chordates have muscle blocks the tail, where the anus is located. present, Fins and tail present, Nature of body covering, Sense organs such as eyes present, Habitat, Segmented body. Muscle blocks are modified body Chordates, however, usually have a Lancelets are similar to fishes Lancelets have a long, tubular $ Indicate on your data table if the following can easily be body shape; length close to 50 segments that consist of stacked mus- tail that extends beyond the anus. Lancelets belong to the subphylum observed: gill slits, notochord, dorsal hollow nerve cord. LS cle layers. You have probably seen You can observe many of the chor- Cephalochordata. They are small, mm, head region, tail-like poste- P Assessment muscle blocks when you ate a cooked date traits in a lancelet in the streamlined, and common marine Analysis rior; smooth body; no sense fish. The blocks of muscle cause the MiniLab on the next page. animals, usually about 5 cm long, as organs. Students will not be able Knowledge Ask students 1. How does Branchiostoma differ structurally from a fish? Figure 29.10 shows. They spend How are its general appearance and habitat similar to to see a notochord, gill slits, or a to separate the following animals P most of their time buried in the sand those of a fish? dorsal hollow nerve cord. into groups based on LSthe type of with only their heads sticking out. 2. Explain why you were not able to see gills, notochord, and Diversity of Analysis nervous system each has. Their Figure 29.9 a Like tunicates, lancelets are filter a dorsal hollow nerve cord. lists should identify animals that Tunicate larvae are Invertebrate Chordates 3. Using its scientific name as a guide, where might the habi- 1. It has no sense organs, gills, about 1 cm long and feeders. Unlike tunicates, however, have a ventral nerve cord, those The invertebrate chordates belong tat of this species be located? or fins. But it does have a dis- LS are able to swim freely lancelets retain all their chordate fea- that have a dorsal hollow nerve through the water (a). to two subphyla of the phylum tures throughout life. tinct head area. Fishes are cord, and those that have some As adults, tunicates chordata: subphylum Urochordata, classified in the same phylum other nervous system arrange- become sessile filter the tunicates (TEW nuh kaytz), also as lancelets—Chordata—but ment: earthworm, snail, pla- feeders enclosed in a called sea squirts, and subphylum Figure 29.10 Oral hood with tentacles in subphylum Vertebrata, tough, baglike layer of Cephalochordata, the lancelets. Lancelets usually spend most of their narian, sea star, tunicate, clam, tissue called a tunic (b). time buried in the sand with only their whereas lancelets are in sub- grasshopper, lancelet, spider, heads sticking out so they can filter tiny phylum Cephalochordata. Tunicates are sea squirts Dorsal hollow human. L3 morsels of food from the water (a). The nerve cord 2. These structures are all inter- b Members of the subphylum Uro- lancelet’s body looks very much like a nal organs. chordata are commonly called tuni- typical chordate embryo (b). 3. in the ocean along the coast ResourceResource cates, or sea squirts. Although adult of California ManagerManager tunicates do not appear to have any Notochord Mouth shared chordate features, the larval Gill slits P BioLab and MiniLab Work- stage, as shown in Figure 29.9, has a in pharynx Assessment tail that makes it look similar to a sheets, p. 130 L2 Intestine Portfolio Have students tadpole. Tunicate larvae do not feed, Muscle blocks and are free swimming only for a few write a paragraph explaining why LS days after hatching. Then they settle lancelets are important in evolu- a tion. Use the Performance Task and attach themselves with a sucker b to boats, rocks, and the ocean bot- Assessment List for Writing in tom. Many adult tunicates secrete a Anus Science in PASC, p. 87. L2 P P 796 LS Alternative Lab Materials high-power magnification. notochord, gill slits, muscle blocks, tail. 2. What does the symmetry of the larva Assessment LS compound microscope, prepared slides of 2. Draw a diagram of each stage in the 6. Note the fishlike form of the lancelet. of a sea urchin imply about the evolu- Skill Set up microscopes with sea urchin development, prepared slides of order listed. Label each diagram with tionary relationship between echino- Comparison of Sea Urchins Expected Results slides showing features of lanceletsP and lancelets the name of the stage. derms and chordates? Echinoderms are and Lancelets Students should see all of the features various stages of sea urchin develop- 3. Note how the size of the blastula com- closely related to chordates. P Procedure listed above. ment. Ask students to identify the part pares with the size of the zygote. Note 3. What features of the lancelet place it Give students the following directions. Analysis or sequence of development and state Purpose also the size of the cells at each stage. in the phylum Chordata? dorsal hollow 1. Observe slides of the unfertilized sea 1. How does the size of the sea urchin the importance of the part for chordates.LS Students will compare sea urchin larvae 4. Examine a prepared slide of a lancelet. nerve cord, notochord, gill slits, muscle urchin egg, zygote, 2-cell stage, 4-cell blastula compare with that of the Use the Performance Task Assessment with adult lancelets. 5. Find the following parts of the lance- blocks, tail LS stage, 8-cell stage, blastula, gastrula, zygote? The blastula and the zygote List for Making Observations and let and label them on a diagram you and sea urchin larvae. Use low-power are the same size. The cells become Inferences in PASC, p. 17. L2 796 magnification at first, then switch to make: dorsal hollow nerve cord, smaller as development proceeds. 797

P

LS Although lancelets look somewhat Interpreting Scientific 3 Assess IINSIDENSIDE INSIDENSIDE similar to fishes, they have only one Problem-Solving Lab 29-2 I Illustrations TORY layer of skin, with no pigment and no Check for Understanding S STORY scales. Lancelets do not have a dis- P What does a slice through an invertebrate chordate Ask students to list invertebrate tinct head, but they do have light show? Why are tunicates and lancelets important? Being chordate characteristics. L1 Purpose A Tunicate sensitive cells on the anterior end. invertebrate chordates, they show three major structures that Students will learn about the They also have a hood that covers are present at some time during all chordate development. the mouth and the sensory tentacles Reteach structural and behavioral charac- unicates, or sea squirts, are a group of about 1250 species Analysis LS surrounding it. The tentacles direct teristics of tunicates. Tthat live in the ocean. They may live near the shore or at The diagram at Visual-Spatial Give student great depths. They may live individually, or several animals may the water current and food particles right shows a cross groups a large piece of Teaching Strategies share a tunic to form a colony. toward the animal’s mouth. section of an inver- A paper. Have them diagram a lan- tebrate chordate. B Ask students to compare the Critical Thinking In what ways are sponges and tunicates alike? Your task is to celet and label its typical inverte- filter feeding of tunicates with Origins of Invertebrate determine what the C brate chordate parts and their Purple bell tunicate the filter feeding of sponges and Chordates various structures functions. L2 ELL P bivalves. marked A-F are. Because sea squirts and lancelets D 1 Excurrent siphon Water leaves 2 Incurrent siphon Water comes Extension Visual Learning the body of the animal through have no bones, shells, or other hard Water into the animal through the incurrent parts, their fossil record is incom- Ask students toP research the Review with students the char- the excurrent siphon. When a siphon, the animal’s mouth. E tunicate is disturbed, it may plete. Biologists are not sure where phyla Hemichordata andLS Chae- acteristics of tunicates that forcefully spout water from its Mouth sea squirts and lancelets fit in the tognatha. Ask them to report F make them invertebrate chor- mouth and excurrent siphon phylogeny of chordates. According to about the structural and behav- P dates. simultaneously. 3 Ciliated groove one hypothesis, echinoderms, inver- ioral adaptations of these animals During filter feeding, LS Show students live specimens tebrate chordates, and vertebrates all and their evolutionary relation- of tunicates and have them food is trapped by mucus secreted in a arose from ancestral sessile animals ships with echinoderms and compare the specimens with ciliated groove. The that fed by capturing food in tenta- Thinking Critically chordates. L3 the diagram. food and mucus are cles. Modern vertebrates probably 1. What three structures are present in all chordates at LS digested in the ani- arose from the free-swimming larval some time during their development? Does the cross- Critical Thinking mal’s intestine. stages of ancestral invertebrate chor- section diagram of the lancelet confirm your answer? Assessment Sponges and tunciates are both 6 Pharynx The pharynx dates. Recent discoveries of fossil Explain. Performance Have stu- filter feeders. is lined with gill slits forms of organisms that are similar to 2. How would you know that the cross section was not and cilia. The beating living lancelets in rocks 550 million from an echinoderm? dents plan anP exhibit for tunicates of the cilia causes a cur- Gill slits years old show that invertebrate 3. How might the cross section differ if it were taken at a public aquarium. Ask them to rent of water to move from an adult tunicate? A young developing tunicate? include in their plan suggestions through the animal. chordates probably existed before Problem-Solving Lab 29-2 about capture, transport, habitat, P Food is filtered out, vertebrate chordates. and dissolved oxygen is 4 Heart The heart of feeding, andLS general maintenance. Purpose removed from the the tunicate is unusual L2 COOP LEARN water in the pharynx. Students will interpret a cross- because it pumps blood Anus in one direction for Section Assessment P section sliceLS of a lancelet. several minutes and then reverses direction. Understanding Main Ideas more closely related to invertebrate chordates Process Skills Reproductive 1. Describe the four features of chordates. than to echinoderms? 4 Close 2. How are invertebrate chordates different from organs SKILL REVIEWEVIEW interpret scientific illustrations, Esophagus vertebrates? S R ActivityLS observe and infer, think critically Intestine Stomach 3. Compare the physical features of sea squirts and 6. Designing an Experiment Assume that you lancelets. have found some tadpolelike animals in the water DevelopP a table that compares Teaching Strategies 4. How do sea squirts and lancelets protect them- near the seashore and that you can raise them in lancelets and tunicates, discussing selves? a laboratory. Design an experiment in which you Review the procedure for which features are common to will determine whether the animals are larvae or vertebrates and invertebrates. making a cross-section slice. Thinking Critically adults. For more help, refer to Practicing Scientific 5 Tunic Tunicates are covered with a layer of tissue called a Review the orientation of the tunic. Some tunics are thick and tough, and others are thin 5. What features of chordates suggest that you are Methods in the Skill Handbook. LS cross-section slice in relation to and translucent. All protect the animal from predators. ResourceResource the whole animal. Use a cucum- ManagerManager ber to illustrate the view and ori- 798 ECHINODERMS AND INVERTEBRATE CHORDATES 29.2 INVERTEBRATE CHORDATES 799 entation by making a cross-section Content Mastery, pp. 141, slice through the fruit. 143-144 2. Echinoderms would have tube feet and a L1 Assessment Reinforcement and Study Thinking Critically water vascular system, but no noto- Section Assessment Performance Ask students to draw Guide, p. 130 L2 1. Gill slits, muscle blocks, chord, dorsal hollow nerve cord, gill an events chain that sequences the steps they 1. notochord, dorsal hollow nerve cord, gill 4. Sea squirts are covered with a thick tunic, notochord, dorsal hollow slits, or muscle blocks. would need to take to determine that a speci- slits, muscle blocks and lancelets bury themselves in sand. nerve cord; student answers 3. An adult tunicate would have gill slits men is a lancelet rather than an immature 2. In invertebrate chordates, the notochord 5. notochord, gill slits, muscle blocks, and should agree that these are but no notochord or dorsal hollow nerve fish. Use the Performance Task Assessment is not replaced by a backbone. dorsal hollow nerve cord present. cord. A young developing tunicate has List for Events Chain in PASC, p. 91. L2 3. Sea squirts are small, tubular, stationary 6. Watch the animals for several weeks to all of these structures. filter feeders. Lancelets are shaped like see if they change their body shape and fishes and can swim freely, but they symmetry. Watch for reproductive behav- P P spend most of their time buried in the ior or release of gametes. 798 sand. 799 LS LS P

LS VESTIGATE INVESTIGATE IN E INVESTIGATE Observing Sea Urchin Gametes and Egg Development

P ea urchins are typical of most echinoderms in that Time Allotment S their sexes are separate, fertilization is external, AANALYZENALYZE ANDAND CCONCLUDEONCLUDE One class period the first day; 15 and development of a fertilized egg is quite rapid. minutes the second day LS Thus, these animals are excellent choices for studying 1. Sperm are motile, thousands Process Skills gametes, watching fertilization, and observing are present on a slide, the size is close to 10 µm; eggs are not make and use tables, collect data, changes occurring in a fertilized egg. Red sea motile, fewer than 100 on a urchin communicate, compare and con- slide, size is close to 150 µm. trast, measure in SI, observe and female sea urchin. Share gamete sperm to the slide with egg cells cells. using a clean dropper, the other 2. Student answers may vary; infer, organize data, use numbers PPREPARATIONREPARATION 9. Use a clean dropper to transfer a partner should observe under low fertilization is external, so Safety Precautions Problem Materials drop of sperm from the beaker to a power. chances of a sperm meeting How can you induce a sea urchin live sea urchins beakers microscope slide. Observe under 13. Observe the process of fertiliza- Caution students to use care an egg are less; a large num- to release its gametes? sea water petri dish low power without a cover slip. tion and note any changes that when working with syringes and ber of gametes released glass slides and dropper 10. Add a cover slip and observe occur to the egg. Record your improves the chances of fer- chemicals. Make sure they return Objectives cover slips microscope under high power. Note the observations in a data table. tilization. syringes to the designated place. In this BioLab, you will: syringe filled with test tube movement of sperm. Draw several 14. When fertilization has been 3. Induce sea urchins to release their potassium chloride sperm cells and indicate their size accomplished, place the fertilized Sperm tend to cluster around PPREPARATIONREPARATION gamete cells. in µm. Note the approximate eggs in a test tube filled with 10 the outer edge of the egg. Observe living sperm and egg cells Safety Precautions number of sperm cells present. mL of seawater. Label your tube 4. A fertilized egg forms a clear under the microscope. Always wear goggles in the lab. 11. Repeat steps 9 and 10 for egg and observe the eggs 24 hours membrane around the out- Alternative Materials Observe developmental changes in cells. In step 10, use only low later under low power. Record any side edge of the egg shortly Skill Handbook If time and cost prohibit the a fertilized sea urchin egg. power to observe egg cells. changes that you see. CAUTION: after fertilization. Skill Handbook purchase of live sea urchins, Use the if you need 12. For this step, work with a partner. Wash your hands immediately additional help with this lab. the experiment can be done While one partner transfers some after working with animals. with prepared slides available Assessment from biological supply houses. PPROCEDUREROCEDURE AANALYZENALYZE ANDAND CCONCLUDEONCLUDE Knowledge Have students 1. Fill a small beaker (250 mL) with urchin is male, a milky white correlate their observations of sea sea water. mass of sperm will be present in 1. Compare and Contrast Compare from a fertilized egg? Draw both urchin gametes with the pattern ResourceResource 2. Obtain a live sea urchin from the dish. If it is female, a yellow eggs and sperm, noting numbers eggs in your data table. seen throughout the animal king- ManagerManager your teacher and locate an area of orange mass of eggs will be seen. released, numbers observed dom. Is there that much variation soft tissue next to its mouth. 6. If you have a female sea urchin, under low power, size, and ability between sperm and eggs of differ- BioLab and MiniLab Work- Going Further 3. Using a syringe, your teacher hold her upside down directly to move. Going Further ent species? Use the Performance sheets, pp. 131-132 L2 will insert the needle into this over the seawater-filled beaker 2. Predicting Based on the pattern Project Continue to observe fertilized eggs Task Assessment List for Making soft tissue and inject the syringe and allow the eggs to fall directly of fertilization, predict the reason and note the stages of development. Keep a Observations and Inferences in contents into the sea urchin. into the water. for the large number of gametes record of time after fertilization and corre- PASC, p. 17. L2 4. Turn your animal so that its 7. If your urchin is male, use a drop- released in nature. sponding changes in development. mouth is facing up and place it per to add several drops of sperm 3. Observing Describe the behavior To find out more about in a petri dish. CAUTION: Use from the petri dish to your beaker of sperm when they first come in echinoderm develop- Going Further care in handling live animals. of sea water. contact with an egg. ment, visit the Glencoe Science Web Site. P 5. Wait a minute or two, then 8. Check with your classmates to see 4. Observing How does an unfertil- www.glencoe.com/sec/science Have students determine how check the petri dish. If the sea who has a male and who has a ized egg differ in appearance long sperm cells will remain alive (as judged by their motil- P 800 ECHINODERMS AND INVERTEBRATE CHORDATES 29.2 INVERTEBRATE CHORDATES 801 ity) after being released from LS the male sea urchin.

PPROCEDUREROCEDURE LS Teaching Strategies using. Ordering so that animals arrive To reduce the number of sea urchins Troubleshooting Data and Observation Fertilization membrane appears 2-5 minutes Student groups of at least four are early in the week is recommended. needed, have the first morning class do Some sea urchins may not Students will observe the differ- First cleavage 50-70 minutes recommended. Each student should be Animals are available from biological the injecting and capturing of gametes. release gametes with the initial ences between egg and sperm. Second cleavage 78-107 minutes supply houses. Store sperm and eggs as follows for later assigned a specific duty or role. injection. Repeat if necessary. They will determine that devel- Third cleavage 103-205 minutes Sea urchins will typically arrive in a Use 2 mL of a 0.5M potassium chlo- classes: Cover petri dish with sperm, Make sure that you collect the opmental changes occur within large foam container and can remain ride (KCl) solution for each injection. store in a refrigerator at 10ºC; store same number of syringes as minutes after fertilization. Blastula 6 hours there for at least 24-48 hours before The container in which the urchins eggs in beaker of seawater at same tem- handed out. Gastrula 12-20 hours arrive will contain enough seawater for perature as sperm. Try to use stored 800 classroom use. gametes the same day. Larva 24-48 hours801 Physics Physics Chapter 29 Assessment Chapter 29 Assessment Connection Connection Hydraulics P of Sea Stars SSUMMARYUMMARY Main Ideas Purpose Section 29.1 Main Ideas Vocabulary Summary statements can be used by Students learn the application of Echinoderms have spines or bumps on their ampulla (p. 788) students to review the major con- Many organisms use hydraulic systems to supply Echinoderms endoskeletons, radial symmetry, and water vas- madreporite (p. 789) cepts of the chapter. physical principles to biological pedicellaria (p. 787) LS cular systems. Most move by means of the suc- systems. food and oxygen to, and remove wastes from, cells ray (p. 787) lying deep within the body. Hydraulics is a branch tion action of tube feet. tube feet (p. 788) Using the Vocabulary Teaching Strategies of science that is concerned with the practical Echinoderms include sea stars, sea urchins, sand water vascular system To reinforce chapter vocabulary, use applications of liquids in motion. In living sys- dollars, sea cucumbers, sea lilies, and feather (p. 789) Have students refer to the the Content Mastery Booklet and tems, hydraulics is usually concerned with the use stars. Inside Story of a sea star earlier the activities in the Interactive Tutor of water to operate systems that help organisms Deuterostome development, an internal skele- in this chapter to see how the for Biology: The Dynamics of Life on find food and move from place to place. ton, and bilaterally symmetrical larvae are indi- water vascular system is con- cators of the close phylogenetic relationship the Glencoe Science Web Site. nected to the ampullas and tube between echinoderms and chordates. www.glencoe.com/sec/science feet. Explain that hydraulics is the he sea star uses a unique hydraulic mechanism practical application of liquids in Tcalled the water vascular system for move- Section 29.2 Main Ideas Vocabulary All Chapter motion and that in living systems ment and for obtaining food. The water vascular Chordates have a dorsal hollow nerve cord, a dorsal hollow nerve Assessment Sea star opening a mollusk to feed Invertebrate notochord, muscle blocks, gill slits, and a tail at cord (p. 795) the liquid is usually water. The system provides the water pressure that operates gill slit (p. 796) questions and answers have been some stage during development. term hydraulic means “operated, the tube feet of sea stars and other echinoderms. Chordates notochord (p. 795) validated for accuracy and suitabil- moved, or effected by water.” on the water, forcing it into the tube foot’s sucker Sea squirts and lancelets are The water vascular system ity by The Princeton Review. Have students discuss how On the upper end, causing it to extend. invertebrate chordates. surface of a sea star is a sievelike disk, the madre- When the extended tube foot touches a rock Vertebrate chordates may flow of fluids in the body is porite, which opens into a fluid-filled ring. or a mollusk shell, the center of the foot is have evolved from larval stages NDERSTANDING AIN DEAS essential to life. Topics might Extending from the ring are long radial canals retracted slightly. This creates a vacuum, UUNDERSTANDING MMAIN IIDEAS include the delivery of oral med- of ancestral invertebrate running along a groove on the underside of each enabling the tube foot to adhere to the rock or chordates. ication, distribution of hormones of the sea star’s rays. Many small lateral canals shell. The tip of the tube foot also secretes a 1. c secreted by glands, or the re- branch off from the sides of the radial canals. sticky substance that helps it adhere. To move 2. c moval of toxic substances in urine. Each lateral canal ends in a hollow tube foot. forward, muscles in the ampulla relax, and mus- 3. a L1 The tube foot has a small muscular bulb at one cles in the tube foot wall contract. These actions 4. d end, the ampulla, and a short, thin-walled tube shorten the tube foot and pull the sea star for- 5. b Connection to Biology at the other end that is usually flattened into a ward. Water is forced back into the relaxed UUNDERSTANDINGNDERSTANDING MMAINAIN IIDEASDEAS 3. When a sea star loses a ray, it is replaced by sucker. Each ray of the sea star has many tube ampulla. When the muscles in the ampulla con- the process of ______. Scallops take in water and then feet arranged in two or four rows on the bottom tract, the tube foot extends again. This pattern of 1. Sea stars, sea urchins, sand dollars, sea a. regeneration c. metamorphosis clap their shells together, forcing side of the ray. The tube feet are extended or extension and retraction of tube feet results in cucumbers, sea lilies, and feather stars are b. reproduction d. parthenogenesis water out quickly to move the retracted by hydraulic pressure in the water vas- continuous movement. It is the coordinated examples of echinoderms that all have 4. Animals that have spines or bumps on their animal in the opposite direction cular system. movement of many tube feet that enable the sea ______. endoskeletons, radial symmetry, and water from the water flow. Earthworms star to move slowly along the ocean floor. a. exoskeletons vascular systems are ______. Mechanics of the water vascular system The have a hydrostatic skeleton (rigid, b. jointed appendages a. invertebrate chordates entire water vascular system is filled with water P CONNECTION TO BIOLOGYIOLOGY c. tube feet b. chordates water-filled coelom) that their and acts as a hydraulic system, allowing the sea C B d. larvae with radial symmetry c. vertebrates muscles brace against for move- star to move. The muscular ampulla contracts In what way do scallops and earthworms also use d. echinoderms ment through the soil. and relaxes with an action similar to the squeez- hydraulic pressure for locomotion? 2. Of the following, which is NOT a character- ing of a dropper bulb. When the muscles in the istic of chordates? 5. A close phylogenetic relationship between LS wall of the ampulla contract, a valve between the To find out more about hydraulic a. dorsal hollow nerve cord echinoderms and some chordates is indicated lateral canal and the ampulla closes so that water pressure systems, visit the b. notochord by the fact that both have similar ______. does not flow backwards into the radial canal. Glencoe Science Web Site. c. pedicellariae a. habitats c. sizes The pressure from the walls of the ampulla acts www.glencoe.com/sec/science d. muscle blocks b. larvae d. gills

802 ECHINODERMS AND INVERTEBRATE CHORDATES CHAPTER 29 ASSESSMENT 803

Internet Address Book Resource Manager Note Internet addresses VIDEODISC VIDEOTAPE Chapter Assessment, pp. 169-174 The Secret of Life that you find useful in MindJogger Videoquizzes the space below for quick reference. MindJogger Videoquizzes Action of Tube Feet Chapter 29: Echinoderms and Invertebrate Computer Test Bank Chordates BDOL Interactive CD-ROM, Chapter 29 Have students work in groups as they play quiz the videoquiz game to review key chapter !7;FBD" concepts. 802 803 Chapter 29 Assessment Chapter 29 Assessment Chapter 29 Assessment Chapter 29 Assessment

6. b 6. Spines on sea stars and sea urchins are modi- 15. Examine the diagram below. From which 23. Relate the various functions of the water vas- 23. Tube feet enable sea stars to AASSESSINGSSESSING KKNOWLEDGENOWLEDGE && SSKILLSKILLS 7. a fied into pedicellariae used for ______. group did brittle stars most likely evolve? cular system to the environment in which move and open bivalve mol- a. feeding c. breathing echinoderms live. 8. c The diagrams below represent cross sections lusks for food. Tube feet are b. protection d. reproduction 9. d 24. How is the ability of echinoderms to regen- of larvae. The intestines are shown in red also used for gas exchange and 10. d 7. The water vascular system operates the tube erate an adaptive advantage to these animals? and the nerve cords are shown in blue. excretion. This water vascular 11. release feet of sea stars and other echinoderms by 25. Explain how a sea squirt maintains homeosta- system works well in a water 12. notochord means of ______. sis. environment. a. water pressure c. water pumps 13. light or dark 24. Regeneration enables a sea star b. water exchange d. water filtering 14. strong and flexible to survive and escape an attack 8. Tube feet, in addition to functioning in loco- TTHINKINGHINKING CCRITICALLYRITICALLY 15. asteroids by a predator. If a predator motion, also function in ______. 26. Observing and Inferring Explain why the 16. filter feeding a. gas exchange and digestion bites off a ray, the sea star can tube feet of a sand dollar are located on its A B C 17. evolved later b. A B C escape while the predator is digestion and circulation upper surface as well as on its bottom surface. 18. sand dollar c. gas exchange and excretion Interpreting Scientific Illustrations Use the feeding on that ray. A new ray 16. Tunicates and lancelets get food by ______. 27. Comparing and Contrasting Compare the 19. invertebrate chordates d. excretion and digestion diagram to answer the following questions. will grow within weeks. 17. Most echinoderms flourished in the pedicellariae of echinoderms with the nema- 20. bilateral symmetry 9. 25. Sea squirts filter feed and take Water enters and leaves the water vascular Paleozoic era. Brittle stars require habitat tocysts of cnidarians. 1. Which of the diagrams shows a cross system of a sea star through the ______. section of a lancelet? in oxygen from the water. They similar to other echinoderms, but they did 28. Concept Mapping Complete the concept a. radial canal c. tube feet a. A maintain a balance with their not flourish during the Paleozoic because map by using the following vocabulary terms: AAPPLYINGPPLYING MMAINAIN IIDEASDEAS b. ampulla d. madreporite b. B watery environment by filtering they most likely ______. ampulla, madreporite, tube feet, water vascu- 10. c. C out what they require and giv- Sea squirts and lancelets are invertebrate 18. A ______is a flat, disc-shaped echinoderm lar system. 21. Sea stars regenerate and the chordates that have ______. without rays, and only minute hairlike spines. d. none of the diagrams ing off wastes into the water. cut-up parts may become new a. pedicellariae All 19. Sea stars are more likely to leave a fossil 2. Which of the diagrams would represent b. exoskeletons sea stars. record than ______such as tunicates and echinoderms segmented worms and echinoderms? c. tube feet 22. Sea squirts are sessile, filter lancelets. a. A TTHINKINGHINKING CCRITICALLYRITICALLY d. larvae with bilateral symmetry have a b. B feeders that can shoot jets of 20. The 11. When a sea cucumber is threatened, it can c. C water to protect themselves. ______1. 26. The tube feet on the upper sur- ______its internal organs. d. none of the diagrams of this larva face are modified to function as 3. 12. The ______is a semirigid, rodlike structure shows its that includes What does the yellow, solid area repre- gills. common to all members of the phylum close rela- sent? 27. Pedicellariae of echinoderms a. nerve cord c. notochord Chordata. tionship to a sievelike pinch potential predators but 13. When a sea star lifts up the tips of its rays, it radial and b. intestines d. spinal cord chordates. 2. lateral canals are not used in capturing prey 4. 4. is detecting ______. What is wrong with diagram C if it rep- and do not have immobilizing connected to resents an invertebrate chordate? 14. Muscle blocks attached to the notochord toxins as do nematocysts. enable chordates to be more ______. a. The notochord is ventral. 3. b. The nerve cord is ventral and there is 28. 1. Water vascular system; 2. no notochord. Ampulla; 3. Tube feet; 4. c. It is too flat. Madreporite TTESTEST––TTAKINGAKING TTIPIP AAPPLYINGPPLYING MMAINAIN IIDEASDEAS d. The intestine should be round. 5. Interpreting Scientific Illustrations All or None 21. If you were an oyster farmer, why would you CD-ROM Using the same color code and the same When filling in answer ovals, remember to fill in be advised not to break apart and throw back For additional review, use the assessment three organs, draw a diagram of a cross the whole oval. A computer will be scoring your any sea stars that were destroying the oyster options for this chapter found on the Biology: The answers. Don’t give the right answer for a prob- section of a larval sea squirt, sea star, 1. a beds? Dynamics of Life Interactive CD-ROM and on the and earthworm. lem only to lose points on it because the computer Glencoe Science Web Site. 2. b 22. couldn’t read your oval. How does a sessile animal such as a sea squirt www.glencoe.com/sec/science 3. c protect itself? 4. b 5. The sea squirt will look 804 CHAPTER 29 ASSESSMENT CHAPTER 29 ASSESSMENT 805 like A, the sea star like B, and the earthworm like B.

804 805 Invertebrates BBIOIODDIGESTIGEST BBIOIODDIGESTIGEST BIOIODIGESTIGEST BBIOIODDIGESTIGEST For a preview of the invertebrate unit, study this BioDigest before you read the chapters. National Science Education Standards: After you have studied the invertebrate chapters, you can use the BioDigest to review the unit. Flatworms UCP.1, UCP.2, UCP.5, C.1, C.4, Flatworms, phylum Platyhelminthes, include 2 Teach C.5, C.6, F.1 free-living planarians, parasitic tapeworms, and parasitic flukes. Flatworms are bilaterally symmet- Activity Invertebrates rical animals with flattened solid bodies and no body cavities. Flatworms have one body opening Visual-Spatial Many of the through which food enters and wastes leave. Prepare ow are jellyfishes, earthworms, sea stars, and butterflies alike? invertebrate phyla are best All of these animals are invertebrates—animals without back- observed in nature films. Select H several nature films that highlight Purpose bones. The ancestors of all modern invertebrates had simple body invertebrates. Ask students to list This BioDigest can be used as an plans. They lived in water and obtained food, oxygen, and other mate- all the invertebrates they see in overview of the invertebrate ani- rials directly from their surroundings, just like present-day sponges, the films, and group the animals mal phyla. You may wish to use jellyfishes, and worms. Some invertebrates have external coverings into phyla. Ask them to identify this unit summary to teach about such as shells and exoskeletons that provide protection and support. the characteristics they used to invertebrates in place of the classify the animals. L2 chapters in the Invertebrate unit. Sponges Cnidarians Visual Learning Key Concepts Sponges, phylum Porifera, are invertebrates Like sponges, cnidarians are made up of two made up of two cell layers. Most sponges are cell layers and have only one body opening. The Interpersonal Ask student Students learn about the phyla of asymmetrical. They have no tissues, organs, or cell layers of a cnidarian, however, are organized Prey Free-living flatworms have groups to make a labeled invertebrates, including sponges, organ systems. Most adult sponges do not move into tissues with different functions. Cnidarians a head end with organs that sense diagram of a planarian worm on from place to place. are named for stinging cells that contain nemato- cnidarians, flatworms, round- the environment. Flatworms can the chalkboard. Ask them how worms, arthropods, and echino- cysts that are used to capture food. Jellyfishes, detect light, chemicals, food, and P corals, sea anemones, and hydras belong to phy- movements in their surroundings. the shape of a planarian reflects derms, as well as the invertebrate lum Cnidaria. its living habits. Planarians are chordates. They learn about cell Jellyfishes and other Nematocyst flattened, thereby enabling them to VITALITAL STATISTICS organization in animals and cnidarians have nemato- slip easily under rocks and debris in VITALITAL STATISTICS cysts on their tentacles. observe differences in physical Flatworms streams. L2 ELL COOPLS LEARN forms as organisms become more Cnidarians Size ranges: Largest, beef tapeworm, length, 30 m complex, with cells organized Size ranges: Smallest: Haliclystus salpinx, jel- Activity P into tissues, and tissues organized Direction of lyfish, diameter, 25 mm; largest: giant jellyfish Roundworms Distribution: Worldwide in soil, marine, water flow medusa, diameter, 2 m; largest coral colony: brackish, and freshwater habitats Visual-SpatialP Provide stu- into organs and organ systems. Roundworms, phylum Nematoda, have a Numbers of species: Great Barrier Reef, length, 2027 km pseudocoelom and a tubelike digestive system dents with binocular micro- Most poisonous: The sting of an Australian Phylum Platyhelminthes: with two body openings. Most roundworms are Class Turbellaria—free-living planarians, scopes, watch glasses, toothpicks, box jelly can kill a human within minutes. free-living, but many plants and animals are LS Distribution: Worldwide in marine, brackish, 3000 species dropping pipettes, and a pla- affected by parasitic roundworms. P 1 Focus and freshwater habitats. Class Cestoda—parasitic tapeworms, narian worm culture.LS Ask them to Numbers of species: 3500 species place a few drops of water in the Phylum Cnidaria Class Trematoda—parasitic flukes, Bellringer Class Hydrozoa—hydroids, 2700 species 8000 species watch glass, then, using a tooth- Bring an assortment of live inver- Class Scyphozoa—jellyfishes, 200 species pick, gentlyLS move a planarian to tebrates into the classroom and Class Anthozoa—sea anemones and corals, the watch glass. Have students 6200 species observe the worm under the have students examine them. Ask P Parasitic roundworms such as microscope and describe its students to identify traits that this Trichinella are contracted these animals share. They should Sponges are filter feeders. A sponge takes in by eating undercooked pork. movement. L1 ELL discover that invertebrates are water through pores in the sides of its body, Other roundworms can be con- animals without backbones. L1 filters out food, and releases the water tracted by walking barefoot on through the opening at the top. contaminated soil. LS ELL P 806 807 CD-ROM P AssessmentAssessment PlannerPlanner Biology:LS The Dynamics Look for the following logos for strategies that emphasize different learning modalities. of Life Portfolio Assessment Exploration: PThe Five Kingdoms Multiple Kinesthetic Activity, p. 808; Linguistic Biology Journal, Assessment, TWE, pp. 812, 813 Disc 3 Meeting Individual Needs, p. 808 VIDEODISC LS P Performance Assessment BioQuest: Biodiversity Park Learning pp. 809, 810 Naturalist Visual Learning, The Secret of Life BioDigest Assessment, TWE, p. 813 Disc 3, 4 Visual-Spatial Activity, pp. 807, p. 810; Check for Understand- Flatworm Cross Section Styles Knowledge Assessment Video: OceanLS Cnidarians 808, 809, 810, 811; Quick Demo, ing, p. 812 BioDigest Assessment, SE, p. 813 Disc 4 pp. 810, 811 LS Skill Assessment Interpersonal Visual Learning, Assessment, TWE, p. 809 p. 807 !7;EtH" 806 807 Invertebrates Invertebrates BBIOIODDIGESTIGEST BIOIODIGESTIGEST BIOIODIGESTIGEST BBIOIODDIGESTIGEST

Activity Mollusks VITALITAL STATISTICS Segmented Worms Activity Visual-Spatial Ask students Slugs, snails, clams, squids, and octopuses are Mollusks Bristleworms, earthworms, and leeches are Visual-Spatial Give each members of phylum Mollusca. All mollusks are Size ranges: Largest: tropical giant clam, members of phylum Annelida, the segmented Leeches have flat- to observe the movement of bilaterally symmetrical and have a coelom, two length, 1.5 m; North Atlantic giant squid, worms. Segmented worms are bilaterally symmet- tened bodies with group of students a live a live land snail. As the snail body openings, a muscular foot for movement, length, 18 m; Pacific giant octopus, length, 10 rical, coelomate animals that have segmented, no setae. Most earthworm in one dish and a moves, ask students to describe and a mantle, which is a thin membrane that sur- m; smallest: seed clam, length, less than 1 mm cylindrical bodies with two body openings. Most species are parasites bristleworm in another dish. Ask its behavior when the antennae rounds the internal organs. In shelled mollusks, Distribution: Worldwide in salt-, fresh-, and annelids have setae, bristlelike hairs that extend that suck blood and them to observe their behavior P body fluids from are touched with a cotton swab. the mantle secretes the shell. brackish water, and on land in moist temper- from body segments, that help the worms move. and movements. Tell students to ate and tropical habitats. Segmentation is an adaptation that provides ducks, turtles, fishes, L1 ELL Classes of Mollusks Numbers of species: these animals with great flexibility. Each segment and mammals. make a table that shows the simi- The three major classes of mollusks are gas- Phylum Mollusca has its own muscles. Groups of segments have dif- larities and differences between MicroscopeLS Activity tropods with one shell or no shell; bivalves with Class Gastropoda—snails and slugs, 80 000 ferent functions, such as digestion or reproduction. earthworms and bristleworms. two hinged shells; and cephalopods. Cephalopods species Earthworms may be obtained Ask studentsP to observe the Class Bivalvia—bivalves, 10 000 species include octopuses, squids, and shelled nautiluses Classes of Segmented Worms from bait shops and bristleworms development of snail eggs with that all have muscular tentacles and are capable Class Cephalopoda—octopuses, squids, and Phylum Annelida has three classes: Hirudinae, hand lenses or binocular micro- of swimming by jet propulsion. All mollusks, nautiluses, 600 species the leeches; Oligochaeta, the earthworms; and can be obtained from biological scopes. except bivalves, have a rough, tongue- Polychaeta, the bristleworms. supply houses or bait shops near LS like organ called a radula used the sea. L2 for obtaining food. Cephalopods, such as VITALITAL STATISTICS ActivityP octopuses, are predators. Kinesthetic Ask students to Gastropods, such as snails, They capture prey using Segmented Worms Size ranges: Largest: giant tropical earth- Assessment set up a saltwater aquarium use their radulas to scrape the suckers on their long algae from rock surfaces. tentacles. worm, length, 4 m; smallest: freshwater Skill Ask students to find and add marine mollusks that can worm, Aeolosoma, length, 0.5 mm objects in the room that have beLS obtained live from the super- Distribution: Terrestrial and marine, brack- ish, and freshwater habitats worldwide, bilateral and radial symmetry. Ask market. Clams, mussels, and oys- them to explainP why they have ters are generally available. Have except polar regions and deserts. Numbers of species: identified particular objects as students care for and make obser- P Phylum Annelida having one type of symmetry or vations of their aquarium. L2 Class Hirudinea—leeches, 500 species another. Objects such as a pencil ELL Bivalves, such as clams, Class Oligochaeta—earthworms, strain food from water 3100 species and a testLS tube have radial sym- by filtering it through Class Polychaeta—bristleworms, metry. If an object has radial sym- their gills. Most bristleworms have a distinct 8000 species metry, it can be divided along any LS head and a body with many setae. P plane through a central axis into roughly equal halves. Objects such as books and chairs have P OCUSOCUS ONON DAPTATIONSDAPTATIONS CD-ROM FF AA bilateral symmetry. If an object Biology: The Dynamics A pseudocoelomate A coelomate LS roundworm segmented worm has bilateral symmetry, it can be of Life Body Cavities divided along only one plane to Exploration: Mollusks An acoelomate form right and left halves that are LS flatworm Disc 4 he type of body cavity an ani- Animals such as roundworms attachment of muscles, mirror images. L2 T mal has determines how large have a fluid-filled body cavity called making movement more it can grow and how it takes in a pseudocoelom that is partly lined efficient. Earthworms have food and eliminates wastes. Acoelo- with mesoderm. Mesoderm is a layer a coelom, a body cavity sur- mate animals, such as planarians, of cells between the ectoderm and rounded by mesoderm in have no body cavity. Water and endoderm that differentiates into which internal organs are digested food particles travel muscles, circulatory vessels, and suspended. The coelom acts through a solid body by the process reproductive organs. The pseudo- as a watery skeleton against Marine flatworm of diffusion. coelom provides support for the which muscles can work. VIDEODISC The SecretP of Life Earthworm 808 Digestive tract 809 !7;F$A" BIOLOGYIOLOGY JOURNAL MEETING INDIVIDUAL NEEDS LS Invertebrate Advertisements newspaper to review how such advertise- Visually Impaired Linguistic Ask students to prepare a ments for homes are written. Students Kinesthetic Provide poster board classified newspaper advertisement for should be creative with their language but P cut-outs of flatworms, roundworms, a homesite for three animals, one in each keep the precise habitat requirements of and segmented worms. Ask visually- P of the classes of mollusks. Provide students each animal in mind. L3 impaired students to describe their tactile with a page of the real estate section of the impressions of each worm. L1 LS

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LS Invertebrates Invertebrates BBIOIODDIGESTIGEST BIOIODIGESTIGEST BIOIODIGESTIGEST BBIOIODDIGESTIGEST

Like other members have a greater complexity of structure than those Activity Arthropods Arthropod Origins Visual Learning of class Arachnida, Arthropods most likely evolved from seg- of segmented worms. Because arthropods have Visual-Spatial Ask students Arthropods are bilaterally symmetrical, coelo- the black widow mented worms; they both show segmentation. exoskeletons, fossil arthropods are frequently Ask students to examine the mate invertebrates with tough outer coverings spider has four pairs However, an arthropod’s segments are fused and found, and consequently more is known about to bring in jars of many called exoskeletons and jointed appendages that of jointed legs and their origins than about the phylogeny of worms. photo of the moth and explain types of arthropods. Number the are used for walking, sensing, feeding, and mat- chelicerae, a pair of how it is adapted to its way of jars and pass them from group to ing. Exoskeletons protect and support their soft biting appendages near life. The color provides camouflage group, asking students to write internal tissues and organs. Jointed appendages the mouth. Members of class VITALITAL STATISTICS from predators. Large wings permit allow for powerful and efficient movements. Insecta, the insects, the name of the arthropod and such as this luna Arthropods long-distance flight while conserving obvious arthropod features beside Arthropod Diversity moth, have three Size ranges: Largest insects: tropical stick energy during the gliding parts of pairs of jointed legs insect, length, 33 cm; Goliath beetle, mass, the name. For each arthropod, Two out of three animals on Earth today are the flight. L1 and one pair of 100 g; smallest insect: fairyfly wasp, length, ask them to infer what features arthropods. The success of arthropods can be P antennae for sensing 0.21 mm attributed to adaptations that provide efficient helped to make that particular their environments. Distribution: All habitats worldwide. arthropod successful. L2 gas exchange, acute senses, and varied types of Numbers of species: Quick Demo mouthparts for feeding. Arthropods include Phylum Arthropoda organisms such as spiders, crabs, lobsters, Class Arachnida—spiders and their rela- Visual-Spatial Borrow LS shrimps, crayfishes, centipedes, millipedes, tives, 57 000 species a collection of preserved Quick Demo and the enormously diverse group of Class Crustacea—crabs, shrimps, lobsters, butterflies from a nearby insects. crayfishes, 35 000 species Visual-Spatial Show stu- Class Merostomata—horseshoe crabs, college or museum and call dents a live water strider students’ Pattention to the enor- 4 species P on the surface of pond water in Lobsters, class Class Chilopoda—centipedes, 2500 species mous variety in wing shapes, P Crustacea, have a container with a large surface Class Diplopoda—millipedes, sizes, and colors. L2 antennae and two 10 000 species area. Ask students to hypothe- compound eyes on Class Insecta—insects, 750 000 species size how the water strider stays movable stalks. Their LS LS on top of the water. Ask them mandibles move from LS side to side to seize prey. Activity to identify adaptations the ani- The evolution of jointed Millipedes, class Diplopoda, are Visual-Spatial Provide stu- mal has that enables it to skate appendages with many different herbivores. Millipedes have up to on the water surface. L2 functions probably led to the suc- 100 body segments, and each seg- dents with a culture of cess of the arthropods as a group. ment has two pairs of legs. mealworms. Ask themP to find and make diagrams of the stages of P metamorphosis they find in the Visual Learning FFOCUSOCUS ONON AADAPTATIONSDAPTATIONS culture. L1 ELL Naturalist Ask students to LS examine the diagrams of Insects arthropods on this page and iden- Mosquito LS P mouthparts P tify adaptations that enable each nsects have many adaptations that through your skin to suck up blood. Different Foods for animal to survive in its habitat. Ihave led to their success in the air, In contrast, butterflies and moths Different Stages Butterfly have long, coiled tongues that they L1 on land, in freshwater, and in salt Because insects undergo metamorphosis, mouthparts VIDEODISC extend deep into tubular flowers to water. For example, insects have they often utilize different food sources at The Infinite Voyage sip nectar. Grasshoppers and many LS complex mouthparts that are well different times of the year. For example, LS beetles have hard, sharp mandibles Insects: The Ruling Activity adapted for chewing, sucking, pierc- monarch butterfly larvae feed on milkweed they use to cut off and chew leaves. Class, InsectsP and Their Have students design and con- ing, biting, or lapping. Different leaves, whereas the adults feed on milkweed But the heavy mandibles of staghorn species have mouthparts adapted to flower nectar. Apple blossom weevil larvae Behavior (Ch. 1), 7 min. duct an experiment to determine beetles no longer function as jaws; eating a variety of foods. feed on the stamens and pistils of unopened the effect of temperature on the instead, they have become defensive P If you have ever been bitten by a flower buds, but the adult weevils eat apple weapons used for competition and !7-8J" jumping ability of crickets. L2 mosquito, you know that mosquitoes leaves. Some adult insects, such as mayflies, mating purposes. LS have piercing mouthparts that cut do not eat at all! Instead, they rely on food Grasshopper Caterpillars: Altering stored in the larval stage for energy to mate mouthparts Appearances (Ch. 5), 5 min. P 810 Staghorn beetle and lay eggs. 811 LS !7U`H" MEETING INDIVIDUAL NEEDS LS PROJECT P English Language Learners be able to find include head, thorax, abdo- Hydraulics of Tube Feet CD-ROM Kinesthetic For students who are men, spiracles, claws, flippers, jointed legs, Have students research the science of Biology: The Dynamics of Life English language learners or are kines- cephalothorax, antennae, mouthparts, pedi- hydraulics. Have them describe how Exploration: Arthropods thetic learners, purchase plastic arthropods. palps, chelicerae, compound and simple hydraulics helps to operate the tube feet LS P Disc 4 Ask them to work in groups and point out eyes, wings, tympanum, and mandibles. L2 of echinoderms. Have them compare and features of the arthropods as they pass them ELL COOP LEARN contrast this hydraulic system with other around their group. Features that they might P hydraulic systems in the plant or animal LS kingdom. L3 810 P 811

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LS LS Invertebrates Invertebrates BBIOIODDIGESTIGEST BIOIODIGESTIGEST BIOIODIGESTIGEST BBIOIODDIGESTIGEST Echinoderm Diversity a fluid-filled canal lying above the notochord. Gill The lancelet is an Echinoderms slits are paired openings in the pharynx that, in example of an Reteach Assessment There are five major classes of echinoderms. Echinoderms, phylum Echinodermata, are They include sea stars, brittle stars, sea urchins, some invertebrate chordates, are used to strain invertebrate chor- Ask students to make a table in Portfolio Have students radially symmetrical, coelomate animals with sea cucumbers, sand dollars, sea lilies, and feather food from the water. In other chordates, gill slits date. Notice that which they compare the charac- visit a local zoo or pet shop that hard, bumpy, spiny endoskeletons covered by thin stars. develop into internal gills used for gas exchange. the lancelet’s body epidermis. The endoskeleton is comprised of cal- Muscle blocks are modified body segments con- is shaped like that teristic features of invertebrate maintains a saltwater aquarium. Echinoderms have bilaterally symmetrical lar- cium carbonate. Echinoderms move using a vae, a feature that suggests a close relationship to sisting of stacked muscle layers. Muscle blocks are of a fish even animals. L1 Have them time their visit so they unique water vascular system with tiny, suction- the chordates. anchored by the notochord. though it is a are present when it is feeding cuplike tube feet. Some echinoderms have long Invertebrate chordates have all of these fea- burrowing filter Extension time for echinoderms such as sea spines also used in locomotion. tures at some point in their life cycles. The inver- feeder. tebrate chordates include the lancelets and the stars, brittle stars, and feather Ask students to make a collection The tube feet of a sea star operate Invertebrate Chordates tunicates, also known as sea squirts. stars. Have students watch one of local insects and identify the by means of a hydraulic water vas- All chordates have, at one stage of their life features of these animals that echinoderm as it feeds, then cular system. Sea stars move cycles, a notochord, a dorsal hollow nerve cord, make them adapted to the local describe the behavior of the ani- along slowly by alternately gill slits, and muscle blocks. A notochord is a long, IOIO IGESTIGEST SSESSMENT mal in their portfolios. pushing out and pulling semirigid, rodlike structure along the dorsal side B D A environment. L2 ELL in their tube feet. of these animals. The dorsal hollow nerve cord is P Understanding Main Ideas 8. An octopus belongs to phylum Mollusca because it has a mantle, bilateral symme- Assessment Sea cucumbers have a 1. An animal that is a filter feeder, takes in try, two body openings, and ______. P leathery skin and are water through pores in the sides of its a. an external shell Portfolio Using large flexible. Like most body, and releases water from the top is a b. a muscular foot poster paperLS and markers, and echinoderms, they ______. c. a pseudocoelom CD-ROM move using tube feet. a. roundworm c. sponge their knowledge of invertebrate d. segmentation P Biology: The Dynamics b. gastropod d. lancelet structure, have studentsLS design an 9. Leeches feed by ______. invertebrate that is adapted to liv- of Life 2. Nematocysts are unique to ______. a. grazing on aquatic plants Exploration: Echinoderms a. sponges c. annelids b. stinging prey ing in the school parking lot. Ask b. mollusks d. cnidarians Disc 4 c. filter feeding them to make a diagram and a list 3. An example of a free-living flatworm is a d. sucking blood of adaptations.LS Have students ______. 10. Which of the following characteristics is include their posters in their port- a. planarian c. nematode unique to arthropods? folios. L2 P b. tapeworm d. vinegar-eel a. nematocycts c. filter feeding 4. Which of the following is used by seg- b. jointed appendages d. tube feet 3 Assess mented worms for movement? a. chelicerae Thinking Critically VITALITAL STATISTICS Check for Understanding V S b. nematocysts 4 CloseLS c. setae 1. A radula is to a snail as a(n) ______is Naturalist Set up a lab prac- Echinoderms to a jellyfish. Explain your answer. Size ranges: Largest: sea urchin, diameter, d. water vascular system Activity tical with stations with pre- 2. Why is more known about animals with 19 cm; longest: sea cucumber, length, 60 cm 5. Which of the following are invertebrate Have studentsP conduct an inver- served or live invertebrates. Ask Distribution: Marine habitats worldwide. chordates? hard parts than is known about animals students to identify the phylum Numbers of species: a. sea anemones c. bivalves with only soft parts? tebrate survey of a nearby pond, and group within the phylum to Phylum Echinodermata b. lancelets d. squid 3. In what ways are echinoderms more meadow, wetland, or woodland. which each animal belongs, and Class Asteroidea—sea stars, 1500 species 6. Parasitism is a way of life for most similar to vertebrates than to other inver- If time permits, ask them to com- Class Crinoidea—sea lilies and feather ______. tebrates? pare the types of invertebrates explain the visible features that stars, 600 species LS helped them classify the inverte- a. flukes c. cnidarians 4. You are examining a free-living animal found in different habitats. Class Ophiuroidea—brittle stars, b. sponges d. annelids that had a thin, solid body with two sur- The long, thin arms brates. L2 2000 species faces. Into what phylum is this organism of brittle stars are 7. An example of an animal with no body Class Echinoidea—sea urchins and sand classified? Explain. dollars, 950 species fragile and break easily, cavity is a(n) ______. ResourceResource Class Holothuroidea—sea cucumbers, but they grow back. Brittle a. sea star c. earthworm 5. In what two ways are spiders different 1500 species stars use their arms to walk b. flatworm d. clam from insects? ManagerManager along the ocean bottom. Content Mastery, 812 813 pp. 145-148 L1 P Reinforcement and Study Guide, pp. 131-132 L2 Internet Address Book BIOIODIGESTIGEST ASSESSMENT nematocysts 2. Hard parts leave fossil evidence while soft LS Note Internet addresses that you find useful in the space Understanding Main Ideas parts leave little fossil evidence. below for quick reference. 1. c 4. c 7. b 10. b 3. Echinoderms have bilaterally symmetrical 2. d 5. b 8. b larvae, as do chordates. 3. a 6. a 9. d 4. It belongs to the phylum Platyhelminthes P because it is a free-living flatworm. P 5. Spiders have four pairs of legs; insects have Thinking Critically three. Spiders have chelicerae; insects have 1. nematocyst; a snail obtains food with its many different types of mouthparts. Insects LS 812 radula; a jellyfish obtains its food with have antennae; spiders do not. 813LS