Download Biology, 7e (Campbell) Chapter 32: An Introduction to Animal

Biology, 7e (Campbell)
Chapter 32: An Introduction to Animal Diversity
Chapter Questions
1) Most animals exhibit the following structures or functions except
A) nervous and muscle tissue.
B) unique types of intercellular junctions, such as tight junctions and gap junctions.
C) autotrophic nutrition.
D) sexual reproduction.
E) multicellularity.
Answer: C
Topic: Concept 32.1
Skill: Knowledge
2) Which of the following terms or structures is not associated with animals?
A) eukaryotic
B) cell wall
C) desmosome
D) zygote
E) blastula
Answer: B
Topic: Concept 32.1
Skill: Knowledge
3) A researcher is trying to construct a molecular-based phylogeny of the entire animal kingdom. Assuming that none
of the following genes is absolutely conserved, which of the following would be the best choice on which to base the
phylogeny?
A) genes involved in chitin synthesis
B) collagen genes
C) crystallin genes
D) myosin genes
E) globin genes
Answer: B
Topic: Concept 32.1
Skill: Comprehension
4) Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that
only animals derive their nutrition
A) from organic matter.
B) by preying on animals.
C) by ingesting it.
D) by consuming living, rather than dead, prey.
E) by using enzymes to digest their food.
Answer: C
Topic: Concept 32.1
Skill: Comprehension
5) The young of some insects are merely small versions of the adult, whereas the larvae of other insects look
completely different from adults, eat different foods, and may live in different habitats. Which of the following most
directly favors the evolution of the latter more radical kind of metamorphosis?
A) natural selection of sexually immature forms of insects
B) changes in the homeobox genes governing early development
C) the evolution of meiosis
D) B and C only
E) A, B, and C
Answer: B
Topic: Concept 32.1
Skill: Application
6) What is the correct sequence of the following four events during an animal's development?
1. gastrulation
2. metamorphosis
3. fertilization
4. cleavage
A) 4, 3, 2, 1
B) 4, 3, 1, 2
C) 3, 2, 4, 1
D) 3, 4, 2, 1
E) 3, 4, 1, 2
Answer: E
Topic: Concept 32.1
Skill: Comprehension
7) At which stage would one be able to first distinguish a diploblastic embryo from a triploblastic embryo?
A) fertilization
B) cleavage
C) gastrulation
D) organogenesis
E) metamorphosis
Answer: C
Topic: Concept 32.1
Skill: Comprehension
8) Which of the following is not unique to animals?
A) cells that have tight junctions, desmosomes, or gap junctions
B) the structural protein collagen
C) nervous conduction and muscular movement
D) regulatory genes called Hox genes
E) sexual reproduction
Answer: E
Topic: Concept 32.1
Skill: Knowledge
9) The number of legs an insect has, or the number of vertebrae in a vertebral column, or the number of joints in a digit
(such as a finger) are all strongly influenced by ________ genes.
A) haploid
B) introns within
C) heterotic
D) heterogeneous
E) Hox
Answer: E
Topic: Concept 32.1
Skill: Knowledge
10) What should animals as diverse as corals and monkeys have in common?
A) body cavity between body wall and digestive system
B) number of embryonic tissue layers
C) type of body symmetry
D) presence of Hox genes
E) degree of cephalization
Answer: D
Topic: Concept 32.1
Skill: Comprehension
11) What may have occurred to prevent species that are of the same grade from also belonging to the same clade?
A) similar structures arising independently in different lineages
B) convergent evolution among different lineages
C) adaptation by different lineages to the same selective pressures
D) A and B only
E) A, B, and C
Answer: E
Topic: Concept 32.1
Skill: Comprehension
12) The Hox genes came to regulate each of the following in what sequence, from earliest to most recent?
1. identity and position of paired appendages in protostome embryos
2. formation of channels in sponges
3. anterior-posterior orientation of segments in protostome embryos
4. positioning of tentacles in cnidarians
5. anterior-posterior orientation of somites in vertebrate embryos
A) 4, 1, 3, 2, 5
B) 4, 2, 3, 1, 5
C) 4, 2, 5, 3, 1
D) 2, 4, 5, 3, 1
E) 2, 4, 3, 1, 5
Answer: E
Topic: Concept 32.1
Skill: Application
13) Almost all of the major animal body plans seen today appeared in the fossil record over 500 million years ago at the
beginning of the
A) Cambrian period.
B) Ediacaran period.
C) Permian period.
D) Carboniferous period.
E) Cretaceous period.
Answer: A
Topic: Concept 32.2
Skill: Knowledge
14) Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran
fauna?
A) true tissues
B) mineralized hard parts
C) bilateral symmetry
D) cephalization
E) embryos
Answer: B
Topic: Concept 32.2
Skill: Comprehension
15) Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of
predator-prey relationships?
A) increased incidence of worm burrows in the fossil record
B) increased incidence of larger animals in the fossil record
C) increased incidence of organic material in the fossil record
D) increased incidence of fern galls in the fossil record
E) increased incidence of hard parts in the fossil record
Answer: E
Topic: Concept 32.2
Skill: Application
16) Which of these genetic processes may be most helpful in accounting for the Cambrian explosion?
A) binary fission
B) mitosis
C) random segregation
D) gene duplication
E) chromosomal condensation
Answer: D
Topic: Concept 32.2
Skill: Comprehension
17) Whatever its ultimate cause(s), the Cambrian explosion is a prime example of
A) anagenesis (phyletic evolution).
B) evolutionary stasis.
C) adaptive radiation.
D) A and B only
E) A, B, and C
Answer: C
Topic: Concept 32.2
Skill: Comprehension
18) Fossil evidence indicates that the following events occurred in what sequence, from earliest to most recent?
1. Protostomes invade terrestrial environments.
2. Cambrian explosion occurs.
3. Deuterostomes invade terrestrial environments.
4. Vertebrates become top predators in the seas.
A) 2, 4, 3, 1
B) 2, 1, 4, 3
C) 2, 4, 1, 3
D) 2, 3, 1, 4
E) 2, 1, 3, 4
Answer: C
Topic: Concept 32.2
Skill: Comprehension
19) If one encounters the deepest stratum in which aquatic and flying reptiles can be found, then one has likely found a
stratum that was laid during which era?
A) Mesozoic
B) Paleozoic
C) Cenozoic
D) Neoproterozoic
E) Precambrian
Answer: A
Topic: Concept 32.2
Skill: Comprehension
20) What is the probable sequence in which the following clades of animals originated, from earliest to most recent?
1. tetrapods
2. vertebrates
3. deuterostomes
4. amniotes
5. bilaterians
A) 5, 3, 2, 4, 1
B) 5, 3, 2, 1, 4
C) 5, 3, 4, 2, 1
D) 3, 5, 4, 2, 1
E) 3, 5, 2, 1,4
Answer: B
Topic: Concept 32.2
Skill: Comprehension
21) During which era did the greatest radiation of mammals occur?
A) Mesozoic
B) Paleozoic
C) Cenozoic
D) Neoproterozoic
E) Precambrian
Answer: C
Topic: Concept 32.2
Skill: Knowledge
22) The major branches of Eumetazoa are the Radiata and the Bilateria. These names refer to what characteristic of
these animals?
A) size
B) body symmetry
C) embryonic cleavage
D) types of appendages
E) presence or absence of a nucleus in their cells
Answer: B
Topic: Concept 32.3
Skill: Knowledge
23) Organisms showing radial symmetry would likely
A) be good swimmers.
B) have rapid escape behavior.
C) move from place to place relatively slowly, if at all.
D) be able to fly.
E) have many fins.
Answer: C
Topic: Concept 32.3
Skill: Comprehension
24) During metamorphosis, echinoderms undergo a transformation from motile larvae to a sedentary (and sometimes
sessile) existence as adults. What is true of adults, but not of larvae? Adults should
A) be diploblastic.
B) have radial symmetry.
C) lack mesodermally derived tissues.
D) A and B only
E) A, B, and C
Answer: B
Topic: Concept 32.3
Skill: Comprehension
25) Cephalization is primarily associated with
A) adaptation to dark environments.
B) method of reproduction.
C) fate of the blastopore.
D) type of digestive system.
E) bilateral symmetry.
Answer: E
Topic: Concept 32.3
Skill: Knowledge
26) Cephalization is generally associated with all of the following except
A) bilateral symmetry.
B) concentration of sensory structures at the anterior end.
C) a brain.
D) a longitudinal nerve cord.
E) a sessile existence.
Answer: E
Topic: Concept 32.3
Skill: Comprehension
27) Which of the following is an incorrect association of an animal germ layer with the tissues or organs to which it
gives rise?
A) ectoderm-outer covering
B) endoderm-internal lining of digestive tract
C) mesoderm-nervous system
D) mesoderm-muscle
E) endoderm-internal linings of liver and lungs
Answer: C
Topic: Concept 32.3
Skill: Knowledge
28) You are trying to identify an organism. It is an animal, but it does not have nerve or muscle tissue. It is neither
diploblastic nor triploblastic. It is probably a
A) flatworm.
B) jelly.
C) comb jelly.
D) sponge.
E) nematode.
Answer: D
Topic: Concept 32.3
Skill: Application
Figure 32.1
Figure 32.1 shows a chart of the animal kingdom set up as a modified phylogenetic tree. Use the diagram to answer the
following questions.
29) Which group contains diploblastic organisms?
A) I
B) II
C) III
D) IV
E) V
Answer: A
Topic: Concept 32.3
Skill: Knowledge
30) Which group consists of deuterostomes?
A) I
B) II
C) III
D) IV
E) V
Answer: B
Topic: Concept 32.3
Skill: Knowledge
31) Which group includes both ecdysozoans and lophotrochozoans?
A) I
B) II
C) III
D) IV
E) V
Answer: C
Topic: Concept 32.4
Skill: Knowledge
32) Which two groups are most clearly represented in the Ediacaran fauna?
A) I and II
B) I and III
C) II and IV
D) II and V
E) IV and V
Answer: B
Topic: Concept 32.4
Skill: Knowledge
33) Which of these is the basal group of the Eumetazoa?
A) I
B) II
C) III
D) IV
E) V
Answer: A
Topic: Concept 32.4
Skill: Knowledge
34) Which two groups have members that undergo ecdysis?
A) I and II
B) II and III
C) III and IV
D) III and V
E) IV and V
Answer: C
Topic: Concept 32.4
Skill: Knowledge
35) Organisms that are neither coelomate nor pseudocoelomate should, apart from their digestive systems, have bodies
that
A) are solid with tissue.
B) lack the ability to metabolize food.
C) are incapable of muscular contraction.
D) lack true tissues.
E) lack mesodermally derived tissues.
Answer: A
Topic: Concept 32.3
Skill: Comprehension
36) What distinguishes a coelomate animal from a pseudocoelomate animal is that coelomates
A) have a body cavity, whereas pseudocoelomates have a solid body.
B) contain tissues derived from mesoderm, whereas pseudocoelomates have no such tissue.
C) have a body cavity completely lined by mesodermal tissue, whereas pseudocoelomates do not.
D) have a complete digestive system with mouth and anus, whereas pseudocoelomates have a digestive tract with only
one opening.
E) have a gut that lacks suspension within the body cavity, whereas pseudocoelomates have mesenteries that hold the
digestive system in place.
Answer: C
Topic: Concept 32.3
Skill: Knowledge
37) Which of the following functions is an advantage of a fluid-filled body cavity?
A) Internal organs are cushioned and protected from injury.
B) Organs can grow and move independently of the outer body wall.
C) The cavity acts as a hydrostatic skeleton.
D) A and C only
E) A, B, and C
Answer: E
Topic: Concept 32.3
Skill: Comprehension
38) You have before you a living organism, which you examine carefully. Which of the following should convince you
that the organism is an acoelomate?
A) It responds to food by moving toward it.
B) It is triploblastic.
C) It has bilateral symmetry.
D) It possesses sensory structures at its anterior end.
E) Muscular activity of its digestive system distorts the body wall.
Answer: E
Topic: Concept 32.3
Skill: Application
39) An animal that swims rapidly in search of prey that it captures using visual senses concentrated at its anterior end is
likely to be all of the following except
A) bilaterally symmetrical.
B) coelomate.
C) eumetazoan.
D) diploblastic.
E) cephalized.
Answer: D
Topic: Concept 32.3
Skill: Comprehension
40) The blastopore is a structure that is evident in the
A) zygote.
B) blastula.
C) eight-cell embryo.
D) gastrula.
E) egg and sperm.
Answer: D
Topic: Concept 32.3
Skill: Knowledge
41) The blastopore denotes the presence of an endoderm-lined cavity in the developing embryo, a cavity that is known
as the
A) archenteron.
B) blastula.
C) coelom.
D) germ layer.
E) blastocoel.
Answer: A
Topic: Concept 32.3
Skill: Comprehension
42) Which of the following is descriptive of protostomes?
A) spiral and indeterminate cleavage, blastopore becomes mouth, schizocoelous development
B) spiral and determinate cleavage, blastopore becomes mouth, schizocoelous development
C) spiral and determinate cleavage, blastopore becomes anus, enterocoelous development
D) radial and determinate cleavage, blastopore becomes anus, enterocoelous development
E) radial and determinate cleavage, blastopore becomes mouth, schizocoelous development
Answer: B
Topic: Concept 32.3
Skill: Knowledge
43) Which of the following characteristics generally applies to protostome development?
A) radial cleavage
B) determinate cleavage
C) enterocoelous
D) blastopore becomes the anus
E) archenteron absent
Answer: B
Topic: Concept 32.3
Skill: Knowledge
44) Protostome characteristics include all of the following except
A) a mouth that develops from the blastopore.
B) schizocoelous development.
C) spiral cleavage.
D) indeterminate cleavage.
E) solid masses of mesodermal tissue that split and form the body cavity.
Answer: D
Topic: Concept 32.3
Skill: Comprehension
A student encounters an animal embryo at the eight-cell stage. The four smaller cells that comprise one hemisphere of
the embryo seem to be rotated 45 degrees and lie in the grooves between larger, underlying cells (spiral cleavage). Use
this information to answer the questions that follow.
45) This embryo may potentially develop into any one of these organisms except
A) a turtle.
B) an earthworm.
C) a fruit fly.
D) a crab.
E) a mollusc.
Answer: A
Topic: Concept 32.3
Skill: Comprehension
46) If one were to separate these eight cells and attempt to culture them individually, then what is most likely to
happen?
A) All eight cells will die immediately.
B) Each cell will survive but will experience immediate cessation of further growth and cell division.
C) Each cell will continue development, but only into an inviable embryo that lacks many parts.
D) Each cell will develop into a full-sized, normal embryo.
E) Each cell will develop into a smaller-than-average, but otherwise normal, embryo.
Answer: C
Topic: Concept 32.3
Skill: Comprehension
47) If an undisturbed embryo is allowed to develop further, then one should expect that
A) the first opening of the gastrula will ultimately serve as the mouth.
B) upon metamorphosis, the resulting trochophore larva will gain a notochord.
C) upon gastrulation, a solid ball of cells will be produced.
D) both A and B
E) both B and C
Answer: A
Topic: Concept 32.3
Skill: Comprehension
48) The most ancient branch point in animal phylogeny is that between having
A) radial or bilateral symmetry.
B) a well-defined head or no head.
C) diploblastic or triploblastic embryos.
D) true tissues or no tissues.
E) a body cavity or no body cavity.
Answer: D
Topic: Concept 32.3
Skill: Comprehension
49) With the current molecular-based phylogeny in mind, rank the following from most inclusive to least inclusive.
1. ecdysozoan
2. protostome
3. eumetazoan
4. triploblastic
A) 4, 2, 3, 1
B) 4, 3, 1, 2
C) 3, 4, 1, 2
D) 3, 4, 2, 1
E) 4, 3, 2, 1
Answer: D
Topic: Concept 32.4
Skill: Comprehension
50) What does recent evidence from molecular systematics reveal about the relationship between grades and clades?
A) They are one and the same.
B) There is no relationship.
C) Some, but not all, grades reflect evolutionary relatedness.
D) Grades have their basis in, and flow from, clades.
E) Each branch point on a cladogram is associated with the evolution of a new grade.
Answer: C
Topic: Concept 32.4
Skill: Comprehension
51) What is characteristic of all ecdysozoans?
A) the deuterostome condition
B) some kind of exoskeleton, or hard outer covering
C) a pseudocoelom
D) agile, speedy, and powerful locomotion
E) the diploblastic condition
Answer: B
Topic: Concept 32.4
Skill: Knowledge
52) What kind of data should probably have the greatest impact on animal taxonomy in the coming decades?
A) fossil evidence
B) comparative morphology of living species
C) nucleotide sequences of homologous genes
D) similarities in metabolic pathways
E) the number and size of chromosomes within nuclei
Answer: C
Topic: Concept 32.4
Skill: Comprehension
53) Phylogenetic trees are best described as
A) true and inerrant statements about evolutionary relationships.
B) hypothetical portrayals of evolutionary relationships.
C) the most accurate representations possible of genetic relationships among taxa.
D) theories of evolution.
E) the closest things to absolute certainty that modern systematics can produce.
Answer: B
Topic: Concept 32.4
Skill: Comprehension
54) According to the evidence collected so far, the animal kingdom is
A) monophyletic.
B) paraphyletic.
C) polyphyletic.
D) euphyletic.
E) multiphyletic.
Answer: A
Topic: Concept 32.4
Skill: Knowledge
55) The common ancestor of all animals was probably a
A) bacterium.
B) prokaryote.
C) plant.
D) fungus.
E) protist.
Answer: E
Topic: Concept 32.4
Skill: Knowledge
56) If a multicellular animal lacks true tissues, then it can be classified among the
A) eumetazoans.
B) metazoans.
C) protozoans.
D) lophotrochozoans.
E) hydrozoans.
Answer: B
Topic: Concept 32.4
Skill: Knowledge
57) According to both the molecular- and morphology-based animal phylogenies, the following are all protostomes
except
A) molluscs.
B) echinoderms.
C) segmented worms.
D) insects.
E) spiders.
Answer: B
Topic: Concept 32.4
Skill: Knowledge
58) Which of the following organisms are deuterostomes?
A) molluscs
B) annelids
C) echinoderms
D) chordates
E) both C and D
Answer: E
Topic: Concept 32.4
Skill: Knowledge
59) Which of the following statements concerning animal taxonomy is (are) true?
1. Animals are more closely related to plants than to fungi.
2. All animal clades based on body plan have been found to be incorrect.
3. Kingdom Animalia is monophyletic.
4. Only animals reproduce by sexual means.
5. Animals are thought to have evolved from flagellated protists similar to modern choanoflagellates.
A) 5
B) 1, 3
C) 2, 4
D) 3, 5
E) 3, 4, 5
Answer: D
Topic: Concept 32.4
Skill: Knowledge
60) If the current molecular evidence regarding animal origins is well substantiated in the future, then what will be true
of any contrary evidence regarding the origin of animals derived from the fossil record?
A) The contrary fossil evidence will be seen as a hoax.
B) The fossil evidence will be understood to have been incorrect because it is incomplete.
C) The fossil record will be ignored.
D) Phylogenies involving even the smallest bit of fossil evidence will need to be discarded.
E) Only phylogenies based solely on fossil evidence will need to be discarded.
Answer: B
Topic: Concept 32.4
Skill: Application
The following questions refer to Figure 32.2a (morphological) and Figure 32.2b (molecular) phylogenetic trees of the
animal kingdom.
Figure 32.2A
Figure 32.2B
61) According to the molecular phylogeny, which of these phyla is not monophyletic?
A) Porifera
B) Cnidaria
C) Chordata
D) Phoronida
E) Rotifera
Answer: A
Topic: Concept 32.4
Skill: Comprehension
62) Within the morphological phylogeny, which shared derived character is emphasized to the point of causing several
phyla to be placed in an entirely different branch of the bilaterian clade, relative to their position on the molecular
phylogeny?
A) calcareous spicules
B) bilateral symmetry
C) deuterostomy
D) pseudocoelom
E) cnidocytes
Answer: C
Topic: Concept 32.4
Skill: Comprehension
63) Which distinction is given more emphasis by the morphological phylogeny than by the molecular phylogeny?
A) metazoan and eumetazoan
B) radial and bilateral
C) true coelom and pseudocoelom
D) protostome and deuterostome
E) molting and lack of molting
Answer: D
Topic: Concept 32.4
Skill: Comprehension
64) According to the molecular phylogeny, but not according to the morphological phylogeny, ________ are more
derived than ________.
A) rotifers; phoronids
B) ctenophores; cnidarians
C) ectoprocta; brachiopods
D) arthropods; annelids
E) calcareous sponges; siliceous sponges
Answer: E
Topic: Concept 32.4
Skill: Comprehension
65) Which two phyla below are most closely related to each other in both phylogenies?
A) Annelida and Arthropoda
B) Echinodermata and Chordata
C) Arthropoda and Nematoda
D) Mollusca and Platyhelminthes
E) Ectoprocta and Brachiopoda
Answer: B
Topic: Concept 32.4
Skill: Comprehension
66) Which of these pairs of phyla have more apparent molecular similarity to each other than they have morphological
similarity?
A) Arthropoda and Annelida
B) Cnidaria and Ctenophora
C) Chordata and Ectoprocta
D) Arthropoda and Nematoda
E) Mollusca and Nemertea
Answer: D
Topic: Concept 32.4
Skill: Comprehension
Media Activity Questions
67) As a group, how do poriferans, cnidarians, and platyhelminthes differ from other animal phyla?
A) They are radially symmetrical.
B) They do not have a body cavity.
C) They are triploblastic.
D) They are diploblastic.
E) The lack true tissues.
Answer: B
Topic: Web/CD Activity: Animal Phylogenetic Tree
68) Echinoderms are
A) deuterstomes.
B) parazoans.
C) protostomes.
D) radiata.
E) acoelomates.
Answer: A
Topic: Web/CD Activity: Animal Phylogenetic Tree
69) Protostomes exhibit ________ cleavage; deuterostomes exhibit ________ cleavage.
A) radial and spiral; determinate and indeterminate
B) radial and indeterminate; spiral and determinate
C) radial and determinate; spiral and indeterminate
D) spiral and determinate; radial and indeterminate
E) spiral and indeterminate; radial and determinate
Answer: D
Topic: Web/CD Activity: Animal Phylogenetic Tree
70) Why are annelids, arthropods, and molluscs placed in the same clade?
A) They are triploblastic.
B) They are protostomes.
C) They are bilaterally symmetrical.
D) They are coelomates.
E) They are deuterostomes.
Answer: B
Topic: Web/CD Activity: Animal Phylogenetic Tree
71) At the phylum level, you are most closely related to a(n)
A) clam.
B) sea star.
C) earthworm.
D) jelly.
E) planarian.
Answer: B
Topic: Web/CD Activity: Animal Phylogenetic Tree
Self-Quiz Questions
72) Among the characteristics unique to animals is
A) gastrulation.
B) multicellularity.
C) sexual reproduction.
D) flagellated sperm.
E) heterotrophic nutrition.
Answer: A
73) Which of the following was the least likely factor causing the Cambrian explosion?
A) the emergence of predator-prey relationships between animals
B) the accumulation of diverse adaptations, such as shells and different modes of locomotion
C) the movement of animals onto land
D) the evolution of Hox genes that controlled development
E) the accumulation of sufficient atmospheric oxygen to support the more active metabolism of mobile animals
Answer: C
74) 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.
D) development of a true coelom.
E) adaptation to terrestrial environments.
Answer: C
75) Acoelomates are characterized by
A) the absence of a brain.
B) the absence of mesoderm.
C) deuterostome development.
D) a coelom that is not completely lined with mesoderm.
E) a solid body without a cavity surrounding internal organs.
Answer: E
76) 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.
D) the unpredictable formation of either a schizocoelous or enterocoelous body cavity.
E) a mouth that forms in association with the blastopore.
Answer: B
77) The distinction between the sponges and other animal phyla is based mainly on the absence versus the presence of
A) a body cavity.
B) a complete digestive tract.
C) true tissues.
D) a circulatory system.
E) mesoderm.
Answer: C
78) Which of these is a point of conflict between the phylogenetic analyses presented in Figures 32.10 and 32.11 in
your text?
A) the monophyly of the animal kingdom
B) the existence of the bilaterian clades Lophotrochozoa and Ecdysozoa
C) that sponges are basal animals
D) that chordates are deuterostomes
E) the monophyly of bilaterians
Answer: B
79) What is the main basis for placing the arthropods and nematodes in the Ecdysozoa in one hypothesis of animal
phylogeny?
A) Animals in both groups are segmented.
B) Animals in both groups undergo ecdysis.
C) They both have radial, determinate cleavage, and their embryonic development is similar.
D) The fossil record has revealed a common ancestor to these two phyla.
E) Analysis of genes shows that their sequences are quite similar, and these sequences differ from those of the
lophotrochozoans and deuterostomes.
Answer: E
80) Which of the following combinations of phylum and description is incorrect?
A) Echinodermata-branch of Bilateria, coelom forms from archenteron
B) Nematoda-roundworms, pseudocoelomate
C) Cnidaria-radial symmetry, diploblastic
D) Platyhelminthes-flatworms, acoelomates
E) Porifera-coelomates, mouth from blastopore
Answer: E
81) Which of the following subdivisions of the animal kingdom encompasses all the others in the list?
A) Protostomia
B) Bilateria
C) Radiata
D) Eumetazoa
E) Deuterostomia
Answer: D