TEST YOUR KNOWLEDGE Chapter 32: Introduction to Evolution

MULTIPLE CHOICE: Choose the one best answer. 1. Sponges differ from the rest of the be cause a. they are completely sessile. b. they have radial symmetry and are suspension- feeders. c -theirsimpIe-body structure rLas-notrue-nssues—-- and they have a unique embryology. d. they are not multicellular. e. they have no flagellated cells. 7. Which of the following is not descriptive of a 2.. An. insect larva pseudocoelomate? a. is a miniature version of the adult. a. a body cavity incompletely lined by mesoderm b. is transformed into an adult by molting. b. bilateral symmetry c. ensures more genetic variation in the insect life c. triploblastic cycle. d. true tissues d. is a sexually immature organism specialized e. schizocoelous formation of body cavity for eating and growth. e. is all of the above. 8. According to evidence from developmental genetics, the last common ancestor of the bilateral 3. Cephalization animals may have been a. is the development of bilateral symmetry. a. a parazoan that resembled a sponge. b. is the formation of a coelom by budding from b. a complex animal with a head, a longitudinal the archenteron. nerve cord, and a segmented body with legs. c. is a diagnostic characteristic of deuterostomes. c. a simple bilateral animal with no specializa d. is common in radially symmetrical animals. tion. e. is associated with motile animals that concen d. a colonial flagellated protist. trate sensory organs in a head region. e. a pseudocoelomate such as a roundworm. 4. A true coelom a. is found in deuterostomes. b. is found in protostomes. 9. Which of the following was probably not a factor c. is a fluid-filled cavity completely lined by contributing to the Cambrian explosion? mesoderm. a. the emergence or predator—prey relationships d. may be used as a hydrostatic by soft- between animals bodied coelomates. b. the accumulation of diverse adaptations such e. is all of the above. as shells and different modes of locomotion c. the movement of animals onto land 5. Which of the following is descriptive of proto d. the evolution stomes? of mechanisms that controlled the expression of developmental genes a. radial and determinate cleavage, blastopore e. the accumulation of sufficient atmospheric becomes m.outh oxygen to support the more active metabolism b. spiral and indeterminate cleavage, coelom required of more mobile animals forms as split in solid mass of mesoderm c. spiral and determinate cleavage, blastopore 10. The oldest known animals becomes mouth, S hizocoelous development a. were colonies of flagellated protists. d. spiral and indeterminate cleavage, blastopore b. were acoelomate worms. • becomes mouth, enterocoelous development c. were sponges of the radiata. e. radial and determinate cleavage, enterocoelous d. were soft-bodied creatures from the Ediacaran development, blastopore becomes anus period. e. were from the Cambrian explosion at the 6. A gastrovascular cavity beginning of the Paleozoic era. a. functions in both digestion and circulation and has a single opening. b. has a large incurrent siphon and smaller excur rent pores. c. is found in the phyla Cnidarja, Platy qg helminthes, and Rotifera. d. develops from the hollow blastula stage. p •ot p.z e. forms from a split in mesoderm. :3noif aidzinW ______

Chapter 33: Invertebrates 245

K INTERACTIVE QUESTION 33.10 9. sea urchin List the key characteristics that distinguish the phy 10. hydra lum Echinodermata. 11. planaria a. 12. chambered nautilus

b. Phyla Classes A. Annelida a. Arachnida B. Arthropoda b. Bivalvia C. c. Cephaiopoda P. Echinodermata d. Cestoidea E. Mollusca e. Crustacea E Nematoda f. Echinoidea I Phylum Chordata: The chordates include two invertebrate subphyla and all G. Nemertea g. Gastropoda vertebrates (626) H. Platyhelminthes h. Hirudinea Echinoderms and chordates share deuterostome I. Porifera i. Hydrozoa developmenta.l characteristics but have existed as sep.. J. Rotifera j. Insecta arate phyla for at least 500 million years. k. Oligochaeta 1. Scyphozoa STRUCTURE YOUR KNOWLEDGE m.Turbellaria

1. Return to the concept map or diagram you made MULTIPLE CHOICE: Choose the one best answer. in Chapter 32 of the broad groups in the kingdom 1. Invertebrates include Animalia. Review those evolutionary branch a. all animals except for the phylum Vertebrata. points and then add the major phyla included in b. all animals without backbones. each group. Include common examples of animals c. only animals in each phylum. that use hydrostatic . d. members of the parazoa, radiata, and proto stomes, but not of the deuterostomes. e. all the animals that evolved in the Cambrian TEST YOUR KNOWLEDGE explosion. 2. Which of the following is the best description of the phylum Porifera? MATCHING: Match the following organisms with their a. radial symmetry, diploblastic, cnidocytes classes and phyla. Answers may be used more than once or for not at all. capturing prey b. radial symmetry, triploblastic, nematocysts for protection Phylum Class Organism c. radial symmetry, without true tissues, 1. jelly (jellyfish) choanocytes for trapping food partides d. bilateral symmetry, 2. crayfish pseudocoel, flame cells for excretion 3. snail e. bilateral symmetry, osculum and spongocoel for filtering water 4. leech 3. Which of the following does 5. tapeworm not have a gastrovas cular cavity for digestion? ) 6. cricket a. flatworm b. hydra 7. scallop c. polychaete worm 8. tick d. sea anemone e. fluke 246 Llnit Five: The Evolutionary History of Biological Diversity

4. Why is the phylogenetic position of the lopho 8. Which of the following is either not an excretory phorate animals uncertain? structure or is incorrectly matched with its class? a. They have a distinct lophophore surrounding a. metanephridia—Oligoci-kaeta the mouth that is not found in any other phy b. Malpighian tubules—Echinoidea luni. c. flame cells—Turbellaria b. Their embryonic development resembles that d. thin region of cuticle—Crustacea - - -- ofthe:: deuterostornes- but: molecular: systemat-- e-±ion• across cell membranes—Hydrozoa ics places them closer to the protostomes. 9. Torsion c. They have excretory, sensory, and nervous sys a. is embryonic tems that are most similar to the flatworms, but asymmetric growth that results in a U-shaped the fluid-filled sac that operates their proboscis digestive tract in gastropods. b. is characteristic may be homologous to a coelom. of mollusks. c. is responsible d. They have no representatives in the fossil for the spiral growth of bivalve shells. record, so their evolutionary history is totally unknown. d. describes the thrashing movement of nema todes. e. They have radial symmetry like the radiate but e. is responsible a pseudocoelom like a nematode. for the metamorphosis of insects. 10. 5. Hermaphrodites Bivalves differ from other mollusks in that they a. are predaceous. a. contain male and female sex organs but usually b. cross-fertilize. have no heads and are suspension-feeders. c. have b. include sponges, earthworms, and most shells. insects. ci. have open circulatory systems. e. use a c. are characteristically found in parthenogenic radula to feed as they burrow through rotifers. sand. d. arebothaandb. II. The exoskeleton of e. are a, b, and c. a. functions in protection arid anchorage for mus des. 6. Which of the following is not true of criidaxians? b. is composed a. An alternation of medusa and polyp stage is of chitin and cellulose. c. common in the class Hydrozoa. is absent in millipedes arid centipedes. d. expands b. They use a ring of tentacles armed with sting at the joints when the grows. ing cells to capture prey. e. functions c. They include hydras, jellies, sea anemones, and in respiration and movement. planarians. 12. Which of the following is true of the subgroup d. They have a nerve net that coordinates contrac uniramians? tion of microfilaments for movement. a. The horseshoe crab is the one surviving marine e. They have a gastrovascular cavity. member of this group. b. It 7. Which of the following combinations of phylum contains the primarily aquatic crustaceans. c. and characteristics is incorrect? It contains insects, centipedes, and millipedes, a. Nemertea—proboscis worm, complete diges characterized by their unbrariched appendages. tive tract d. It is characterized by jaw]ike mandibles, anten nae, b. Rotifera—parthenogenesis, crown of cilia, compound eyes, and includes all arthro microscopic animals pods except the chelicerates. e. It includes c. Nematoda—gastrovascular cavity, tough cuti the extinct trilobites and euryp cle, ubiquitous tends. ci. Annelida—segmentation, closed circulation, hydrostatic skeleton e. Echinodermata—radial symmetry, endoskele 6 ton, water vascular system qot q17 :23iozj 3tI UI H •fl q 3 ‘D 0I 1a9 a 6 PH g ID i :Zuzipv SELEQ,UIZc 8. Among the characteristics unique to animals is based 1. The distinction between the parazoans and eumetazoans is a. gastrulation ci flagellated sperm mainly on the absence versus the presence of b. multicellularity e. heterotrophy a. body cavities c. sexual reproduction b. a complete digestive tract 9. Which of the following combinations of phylum and description tissues c. true is incorrect? -. - &-acirculatory system a. Echinodermata—branch e. mesoderm bilateria, coelom from archenteron b. Nematoda_-roundwo pseudocdelomate 2. As a group, acoelomates are tharacterized by c. Cnidaria—radial symmetry, gastrovasciilar cavity a. ga.strovascular cavities d. Platyhelminthes_flatworm, gastrovascuiar cavity (in most b. the absence of mesoden-n species), acoelomate c. deuterostome development e. Porifera—ga.strovascular cavity mouth from llastopore ci a coelom that is not completely lined with mesoderin 10. Which of the following subdivisions of the animal kingdom without a cavity surrounding internal organs e. a solid body encompasses all the others in the list? 3. Which of the following is not descriptive of deuterostomes? a. protostomes ci coelornates a. radial cleavage b. bilateria e. deuterostornes b. includes humans c. pseudocoeloniates c. formation of the coelom from outpocketings of archenteron d. development of the blastopore into the mouth e. echinoderms and chordates 4. The radiata and bilateria of the eumetazoa both exhibit a. cepha]ization b. bilateraI symmetry of larval forms c. dominance of the diploid stage in the life cycle ci.. a complete digestive tract with separate mouth and anus e. three germ layers in embryonic development 5. Bilateral symmetry in the animal kingdom is best correlated with a. an ability to sense equally in all directions b. the presence of a skeleton c. motility and active predation and escape ci development of a true coelorn e. adaptation to terrestrial environments 6. A direct consequence of indeterminate cleavage is a. formation of the archenteron b. the ability of cells isolated from the early embryo to develop into viable individuals c. the arrangement of cleavage planes perpendicular to the egg’s vertical axis ci. the unpredictable forrñation of either a schizocoelous or ente rocoelous body cavity e. a mouth that forms in association with the blastopore

7. Many biologists.suspect that the rapid diversification of bilateral phyla during the Cambrian a. was triggered by declining concentrations of atmospheric car bon dioxide b. was associated with variation in patterns of embryonic development c. followed the development of gastrovascular cavities ci. was possible once cleavage evolved e. was the result of increased solar radiation and an accelerated mutation rate

HAPTER 32 • INTRODUCTION TO ANIMAL EVOLUTION 597