Exam #3 Ch 32, 33, 34

Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If true, this finding would _____. A) mean that sponges must no longer be classified as animals B) confirm the identity of sponges as "basal animals" C) mean that extinct sponges must have been the last common ancestor of animals and fungi D) require sponges to be reclassified as choanoflagellates

B

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 3, 4, 1, 2 4, 2, 3, 1 3, 4, 2, 1 4, 3, 2, 1 4, 3, 1, 2

3, 4, 2, 1

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 5 → 3 → 2 → 4 → 1 3 → 5 → 2 → 1 → 4 5 → 3 → 2 → 1 → 4 3 → 5 → 4 → 2 → 1 5 → 3 → 4 → 2 → 1

5 → 3 → 2 → 1 → 4

An organism that exhibits cephalization probably also _____. A) is bilaterally symmetrical B) has a coelom C) is segmented D) is diploblastic

A

If you think of the earthworm body plan as a drinking straw within a pipe, where would you expect to find most of the tissues that developed from endoderm? A) lining the straw B) lining the space between the pipe and the straw C) forming the outside of the pipe D) forming the outside of the straw

A

In individual insects of some species, whole chromosomes that carry larval genes are eliminated from the genomes of somatic cells at the time of metamorphosis. A consequence of this occurrence is that _____. A) we could not clone a larva from the somatic cells of such an adult insect B) such species must reproduce only asexually C) the descendants of these adults do not include a larval stage D) metamorphosis can no longer occur among the descendents of such adults

A

The most recently discovered phylum in the animal kingdom (1995) is the phylum Cycliophora. It includes three species of tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The body is sac-like and has a U-shaped intestine that brings the anus close to the mouth. Cycliophorans are coelomates, do not molt (though their host does), and their embryos undergo spiral cleavage. Which of these features is LEAST useful in assigning the phylum Cycliophora to a clade of animals? A) having a true coelom as a body cavity B) having a body symmetry that permits a U-shaped intestine C) having embryos with spiral cleavage D) lacking ecdysis (molting)

A

Trichoplax adhaerens (Tp) is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 μm high, are irregularly shaped, and consist of a total of about 2000 cells, which are diploid (2n = 12). There are four types of cells, none of which are nerve or muscle cells, and none of which have cell walls. They move using cilia, and any "edge" can lead. Tp feeds on marine microbes, mostly unicellular green algae, by crawling atop the algae and trapping it between its ventral surface and the substrate. Enzymes are then secreted onto the algae, and the resulting nutrients are absorbed. Tp sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage. Tp's body symmetry seems to be most like that of _____. A) most sponges B) cnidarians C) worms D) tetrapods

A

Two competing hypotheses to account for the increase in the number of Hox genes from the last common ancestor of bilaterians to the last common ancestor of insects and vertebrates are: (1) a single duplication of the entire four-gene cluster, followed by the loss of one gene, and (2) three independent duplications of individual Hox genes. To prefer the first hypothesis on the basis of parsimony requires the assumption that _____. A) the duplication of a cluster of four Hox genes is equally likely as the duplication of a single Hox gene B) there is an actual process by which individual genes can be duplicated C) genes can exist is spatial groupings called clusters D) clusters of genes can undergo disruption, with individual genes moving to different chromosomes during evolution

A

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 → 1 → 4 B) 5 → 3 → 4 → 2 → 1 C) 3 → 5 → 4 → 2 → 1 D) 3 → 5 → 2 → 1 → 4

A

What was an early selective advantage of a coelom in animals? A coelom _____. A) contributed to a hydrostatic skeleton, allowing greater range of motion B) was a more efficient digestive system C) allowed cephalization and the formation of a cerebral ganglion D) allowed asexual and sexual reproduction

A

Which of these, if true, would support the claim that the ancestral cnidarians had bilateral symmetry? 1. Cnidarian larvae possess anterior-posterior, left-right, and dorsal-ventral aspects. 2. Cnidarians have fewer Hox genes than bilaterians. 3. All extant cnidarians, including Nematostella, are diploblastic. 4. β-catenin turns out to be essential for gastrulation in all animals in which it occurs. 5. All cnidarians are acoelomate. A) 1 and 4 B) 2 and 3 C) 2 and 4 D) 4 and 5

A

Which tissue type, or organ, is NOT correctly matched with its germ layer tissue? A) nervous — mesoderm B) muscular — mesoderm C) stomach — endoderm D) skin — ectoderm

A

Which phylum is characterized by animals that have a segmented body? Which phylum is characterized by animals that have a segmented body? A. Arthropoda B. Platyhelminthes C. Mollusca D. Porifera E. Cnidaria

A. Arthropoda

The animal phylum most like the protists that gave rise to the animal kingdom is _____. The animal phylum most like the protists that gave rise to the animal kingdom is _____. A. Porifera B. Ctenophora C. Lycophyta D. Echinodermata E. Cnidaria

A. Porifera

MAKE CONNECTIONS In Figure 33.8 in your textbook, assume that the two medusae shown at step 4 were produced by one polyp colony. Review Concept 12.1 (pp. 229-230 in your textbook) and Concept 13.4 (pp. 257-260 in your textbook), and then use your understanding of mitosis and meiosis to evaluate whether the following sentence is true or false. If false, select the answer that provides the correct reason. Although the two medusae are genetically identical, a sperm produced by one will differ genetically from an egg produced by the other. A. T B. F (neither the medusae or the gametes are genetically identical) C. F (the medusae are not identical but the gametes are) D. F (the medusae are genetically identical, but so are the gametes)

A. T

Which of the following is radially symmetrical? Which of the following is radially symmetrical? A. a doughnut B. an automobile C. a submarine sandwich D. a spoon E. a dog

A. a doughnut

Listed below are four adaptations of terrestrial vertebrates. Which is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle? Listed below are four adaptations of terrestrial vertebrates. Which is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle? A. amniotic eggs B. lungs C. hearts with more than two chambers D. tetrapod locomotion E. All of these are essential for a completely terrestrial existence.

A. amniotic eggs

Most members of which of the following groups are most closely associated with a wet or moist environment? Most members of which of the following groups are most closely associated with a wet or moist environment? A. amphibians B. birds C. mammals D. pterosaurs E. dinosaurs

A. amphibians

The diagnostic feature of Chondrichthyes is _____. The diagnostic feature of Chondrichthyes is _____. A. an endoskeleton of calcified cartilage B. jaws C. a swim bladder D. a lateral line system E. a streamlined, torpedo-shaped body

A. an endoskeleton of calcified cartilage

An important trend in animal evolution was cephalization. An animal is said to show cephalization when it _____. An important trend in animal evolution was cephalization. An animal is said to show cephalization when it _____. A. has an aggregation of sensory neurons at the anterior end B. is large C. has bilateral symmetry D. has tissue specialization E. has a hard, outer covering

A. has an aggregation of sensory neurons at the anterior end

Unlike eutherians, both monotremes and marsupials Unlike eutherians, both monotremes and marsupials A. have some embryonic development outside the uterus. B. are found in Australia and Africa. C. lack nipples. D. include only insectivores and herbivores. E. lay eggs.

A. have some embryonic development outside the uterus.

Select the correct statement(s) about invertebrate taxa. Select all that apply. Select all that apply. A. Rotifers are smaller than many protists. B. Tapeworms lack a mouth and gastrovascular cavity. C. Ectoprocts lack a distinct head.

ALL OF THEM ARE CORRECT

Which of the following statements is correct? Eumetazoans have three embryonic tissue layers. Sponges are diploblastic animals. The origin of all extant animal phyla can be traced to the Cambrian explosion. All animals share a common ancestor. Most animal phyla belong to the clade Radiata.

All animals share a common ancestor. It is thought to have been a protist similar to a choanoflagellate.

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) β-catenin genes D) genes involved in eye-lens synthesis

B

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 to lie in the grooves between larger, underlying cells. This embryo may potentially develop into a(n) _____. A) turtle B) earthworm C) sea star D) sea urchin

B

Among protostomes, which morphological trait has shown the most variation? A) type of symmetry (bilateral vs. radial vs. none) B) type of body cavity (coelom vs. pseudocoelom vs. no coelom) C) number of embryonic tissue types (diploblasty vs. triploblasty) D) type of development (protostome vs. deuterostome)

B

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that most animals derive their nutrition by _____. A) preying on animals B) ingesting it C) consuming living, rather than dead, prey D) using enzymes to digest their food

B

Dll is a gene known to direct limb development in the fruit fly. Researchers studying this gene have found that it is also expressed in developing appendages in animals from many other phyla, supporting the hypothesis that all animal appendages may be homologous. However, suppose researchers looking at Dll activity had instead found the results shown in the figure above. These results suggest instead that _____. A) Dll is not actually involved in appendage development B) appendages evolved separately in protostomes and deuterostomes C) appendages coevolved with segmentation D) all animal appendages are homologous

B

Evidence of which structure or characteristic would be most surprising to find among fossils of the Ediacaran fauna? A) true tissues B) hard parts C) bilateral symmetry D) embryos

B

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 → 1 → 4 → 3 B) 2 → 4 → 1 → 3 C) 2 → 3 → 1 → 4 D) 2 → 1 → 3 → 4

B

If in the future the current molecular evidence regarding animal origins is further substantiated, 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 interpreted incorrectly because it is incomplete. C) The fossil record will henceforth be ignored. D) Phylogenies involving even the smallest bit of fossil evidence will need to be discarded.

B

If we 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 may continue development, but only into a nonviable embryo that lacks many parts. C) Each cell may develop into a full-sized, normal embryo. D) Each cell may develop into a smaller-than-average, but otherwise normal, embryo.

B

In the traditional phylogeny (A), the phylum Platyhelminthes is depicted as a sister taxon to the rest of the protostome phyla and as having diverged earlier from the lineage that led to the rest of the protostomes. In the molecular phylogeny (B), Platyhelminthes is depicted as a lophotrochozoan phylum. What probably led to this change? A) Platyhelminthes ceased to be recognized as true protostomes. B) The removal of the acoel flatworms (Acoela) from the Platyhelminthes allowed the remaining flatworms to be a monophyletic clade clearly tied to the Lophotrochozoa. C) All Platyhelminthes must have a well-developed lophophore as their feeding apparatus. D) Platyhelminthes' close genetic ties to the arthropods became clear as their Hox gene sequences were studied.

B

Suppose a researcher for a pest-control company developed a chemical that inhibited the development of an embryonic mosquito's endodermal cells. Which of the following would be a likely mechanism by which this pesticide works? A) The mosquito would develop a weakened exoskeleton that would make it vulnerable to trauma. B) The mosquito would have trouble digesting food, due to impaired gut function. C) The mosquito would have trouble with respiration and circulation, due to impaired muscle function. D) The mosquito wouldn't be affected at all.

B

The larvae 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 is most directly involved in the evolution of these variations in metamorphosis? A) artificial selection of sexually immature forms of insects B) changes in the homeobox genes governing early development C) the evolution of meiosis D) the origin of a brain

B

The last common ancestor of all bilaterians is thought to have had four Hox genes. Most extant cnidarians have two Hox genes, except Nematostella (of β-catenin fame), which has three Hox genes. On the basis of these observations, some have proposed that the ancestral cnidarians were originally bilateral and, in stages, lost Hox genes from their genomes. If true, this would mean that _____. A) the Radiata should be a true clade B) the radial symmetry of extant cnidarians is secondarily derived, rather than being an ancestral trait C) Hox genes play little actual role in coding for an animal's "body plan" D) the Cnidaria may someday replace porifera as the basal bilaterians

B

The most recently discovered phylum in the animal kingdom (1995) is the phylum Cycliophora. It includes three species of tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The body is sac-like and has a U-shaped intestine that brings the anus close to the mouth. Cycliophorans are coelomates, do not molt (though their host does), and their embryos undergo spiral cleavage. Basing your inferences on information in the paragraph above, to which clade(s) should cycliophorans belong? 1. Eumetazoa 2. Deuterostomia 3. Bilateria 4. Ecdysozoa 5. Lophotrochozoa A) 1 and 3 B) 1, 3, and 5 C) 2, 3, and 4 D) 2, 3, and 5

B

The most recently discovered phylum in the animal kingdom (1995) is the phylum Cycliophora. It includes three species of tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The body is sac-like and has a U-shaped intestine that brings the anus close to the mouth. Cycliophorans are coelomates, do not molt (though their host does), and their embryos undergo spiral cleavage. Which of these, if discovered among cycliophorans, would cause the most confusion concerning our current understanding of cycliophoran taxonomy? A) if the ciliated feeding ring is a lophophore B) if embryos are diploblastic C) if the body cavity is actually a pseudocoelom D) if the organisms show little apparent cephalization

B

We should expect the inner wall of the swim bladder to be lined with tissue that is derived from _____. A) ectoderm B) endoderm C) mesoderm D) mesoglea

B

Which of the following Tp traits is different from all other known animals? A) Tp is multicellular. B) Tp lacks muscle and nerve cells. C) Tp has cilia. D) Tp lacks cell walls.

B

Which of the following is (are) unique to animals? A) the structural carbohydrate, chitin B) nervous system signal conduction and muscular movement C) heterotrophy D) flagellated gametes

B

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. Animals only reproduce sexually. 5. Animals are thought to have evolved from flagellated protists similar to modern choanoflagellates. A) 1 and 2 B) 3 and 5 C) 3, 4, and 5 D) 2 and 4

B

While looking at some seawater through your microscope, you spot the egg of an unknown animal. Which of the following tests could you use to determine whether the developing organism is a protostome or a deuterostome? See whether the embryo _____. A) develops germ layers B) exhibits spiral cleavage or radial cleavage C) develops a blastopore D) develops an archenteron

B

Why might researchers choose to use molecular data (such as ribosomal RNA sequences) rather than morphological data to study the evolutionary history of animals? A) Molecular data can be gathered in the lab, while morphological data must be gathered in the field. B) Sequence data can be gathered faster than morphological data, and morphological data provides a different perspective. C) Morphological changes usually do not result from molecular changes. D) Some phyla vary too widely in morphological characteristics to be classified accurately.

B

Identify the features that distinguish animals from organisms in other multicellular kingdoms. Select all that apply. Select all that apply. A. Animals are motile. B. Animals are ingestive heterotrophs. C. Animals have sensory organs at their anterior end.

B. Animals are ingestive heterotrophs.

Which feature of deuterostome development explains the formation of identical human twins? Which feature of deuterostome development explains the formation of identical human twins? A. Deuterostomes have radial cleavage. B. Deuterostomes have indeterminate development. C. In deuterostomes, the blastopore becomes the anus.

B. Deuterostomes have indeterminate development.

What is the key difference between a coelom and a pseudocoelom? A. Pseudocoeloms arose early in animal evolution and evolved into coeloms. B. Only a coelom is fully lined with mesoderm tissue. C. A coelom is a true body cavity, whereas a pseudocoelom is a false coelom that is not fully functional.

B. Only a coelom is fully lined with mesoderm tissue.

Which of the following is NOT a diagnostic feature of the Chordata? Which of the following is NOT a diagnostic feature of the Chordata? A. a hollow dorsal nerve cord B. vertebrae C. pharyngeal slits or clefts D. a muscular, post-anal tail E. notochord

B. vertebrae

All things being equal, which of these is the most parsimonious explanation for the change in the number of Hox genes from the last common ancestor of insects and vertebrates to ancestral vertebrates, as shown in the table above? A) The occurrence of seven independent duplications of individual Hox genes. B) The occurrence of two distinct duplications of the entire seven-gene cluster, followed by the loss of one cluster. C) The occurrence of a single duplication of the entire seven-gene cluster.

C

As you are on the way to Tahiti for a vacation, your plane crash-lands on a previously undiscovered island. You soon find that the island is teeming with unfamiliar organisms, and you, as a student of biology, decide to survey them (with the aid of the Insta-Lab Portable Laboratory you brought along in your suitcase). You select three organisms and observe them in detail, making the notations found in the figure above. Which organism would you classify as an animal? A) organism A B) organism B C) organism C

C

In the experiment outlined in the figure above, what would you expect to happen if researchers supplied an enzyme that blocked the expression of the Dll gene? A) The embryo would have appendages in abnormal locations. B) The origins of the embryo's appendages would fluoresce. C) The developing embryo would have no appendages. D) The embryo's appendages would be shorter than usual.

C

Nudibranchs, a type of predatory sea slug, can have various protuberances (that is, extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips. If nudibranch rhinophores are located at the anterior ends of these sea slugs, then they contribute to the sea slugs' _____. A) segmentation B) lack of torsion C) cephalization D) identity as lophotrochozoans

C

Soon after the coelom begins to form, a researcher injects a dye into the coelom of a deuterostome embryo. Initially, the dye should be able to flow directly into the _____. A) blastopore B) blastocoel C) archenteron D) pseudocoelom

C

The Hox genes came to regulate each of the following. From earliest to most recent, in what sequence did these events evolve? 1. identity and position of paired appendages in protostome embryos 2. anterior-posterior orientation of segments in protostome embryos 3. positioning of tentacles in cnidarians 4. anterior-posterior orientation in vertebrate embryos A) 4 → 1 → 3 → 2 B) 4 → 2 → 1 → 3 C) 3 → 2 → 1 → 4 D) 3 → 4 → 1 → 2

C

The evolution of animal species has been prolific (the estimates go into the millions and tens of millions). Much of this diversity is a result of the evolution of novel ways to _____. A) reproduce B) arrange cells into tissues C) sense, feed, and move D) form an embryo and establish a basic body plan

C

The most ancient branch point in animal phylogeny is the characteristic of having _____. A) radial or bilateral symmetry B) diploblastic or triploblastic embryos C) true tissues or no tissues D) a body cavity or no body cavity

C

The protostome developmental sequence arose just once in evolutionary history, resulting in two main subgroups—Lophotrochozoa and Ecdysozoa. What does this finding suggest? A) These two subgroups have a common ancestor that was a deuterostome. B) The protostomes are a polyphyletic group. C) Division of these two groups occurred after the protostome developmental sequence appeared. D) The lophotrochozoans are monophyletic.

C

Trichoplax adhaerens (Tp) is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 μm high, are irregularly shaped, and consist of a total of about 2000 cells, which are diploid (2n = 12). There are four types of cells, none of which are nerve or muscle cells, and none of which have cell walls. They move using cilia, and any "edge" can lead. Tp feeds on marine microbes, mostly unicellular green algae, by crawling atop the algae and trapping it between its ventral surface and the substrate. Enzymes are then secreted onto the algae, and the resulting nutrients are absorbed. Tp sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage. 26) On the basis of information in the paragraph above, which of these should be able to be observed in Tp? A) the act of fertilization B) the process of gastrulation C) eggs D) All three of the listed responses are correct.

C

What conclusion is apparent from the data in the table above? A) Land animals have more Hox genes than do those that live in water. B) All bilaterian phyla have had the same degree of expansion in their numbers of Hox genes. C) The expansion in number of Hox genes throughout vertebrate evolution cannot be explained merely by three duplications of the ancestral vertebrate Hox cluster. D) Extant insects all have seven Hox genes.

C

Whatever its ultimate cause(s), the Cambrian explosion is a prime example of _____. A) mass extinction B) evolutionary stasis C) adaptive radiation D) a large meteor impact

C

Which morphological trait evolved more than once in animals, according to the phylogeny based on DNA sequence data found in the figure above? A) coelom B) bilateral symmetry C) segmentation D) protostome development

C

Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion? A) binary fission B) random segregation C) gene duplication D) chromosomal condensation

C

Which of the following is a feature of the tube-within-a-tube body plan in most animal phyla? A) The outer tube consists of a hard exoskeleton. B) The outer tube consists of digestive organs. C) The mouth and anus form the ends of the inner tube. D) The two "tubes" are separated by tissue that comes from embryonic endoderm.

C

What is the significance of the evolution of Hox gene clusters during vertebrate evolution? What is the significance of the evolution of Hox gene clusters during vertebrate evolution? A. Novel Hox genes coded for novel vertebrate features, such as jaws, limbs, and large brains. B. Duplicate Hox genes triggered the formation of neural crest cells and allowed them to disperse throughout the body, forming a variety of structures. C. Duplication of Hox genes made increased morphological complexity possible.

C. Duplication of Hox genes made increased morphological complexity possible.

What evidence suggests that vertebrates are more closely related to echinoderms than are any other invertebrate phyla? A. Shared morphology B. Shared patterns of development C. Shared DNA sequences

C. Shared DNA sequences

Which of the following chordates is most likely to look least like other chordates? Which of the following chordates is most likely to look least like other chordates? A. lancelet B. adult human C. adult tunicate D. embryonic human E. larval tunicate

C. adult tunicate

Which of the following animals does NOT have a body cavity? A. nematode B. clam C. flatworm D. earthworm E. mouse

C. flatworm

The water vascular system of echinoderms A. moves water through the animal's body during suspension feeding. B. is bilateral in organization, even though the adult animal is not bilaterally symmetrical. C. functions in locomotion and feeding. D. is analogous to the gastrovascular cavity of flatworms. E. functions as a circulatory system that distributes nutrients to body cells.

C. functions in locomotion and feeding.

Some species of rotifers consist solely of females. Their method of reproduction is described as _____. Some species of rotifers consist solely of females. Their method of reproduction is described as _____. A. sperm-stealing B. fragmentation C. parthenogenesis D. binary fission E. budding

C. parthenogenesis

Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that _____. A) arthropods evolved before vertebrates did B) extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates C) vertebrates evolved from arthropods D) arthropods have had more time to coevolve with land plants than have vertebrates

D

In examining an unknown animal species during its embryonic development, how can you be sure what you are looking at is a protostome and not a deuterostome? A) There is evidence of cephalization. B) The animal is triploblastic. C) The animal is clearly bilaterally symmetrical. D) You see a mouth, but not an anus.

D

The common ancestor of the protostomes had a coelom. What does this suggest? A) All lophotrochozoans have a coelom. B) There are no pseudocoelomates within the protostomes. C) There are no acoelomates within the protostomes. D) The body cavity evolved before the lophophore.

D

The feeding stage of cycliophorans _____. 1. is autotrophic 2. is sessile 3. captures food in a manner similar to that of animals with lophophores 4. shows radial symmetry A) 1 and 2 B) 1 and 3 C) 2 and 4 D) 1, 2, and 3

D

The last common ancestor of all animals was probably a _____. A) unicellular chytrid B) multicellular algae C) multicellular fungus D) flagellated protist

D

The most recently discovered phylum in the animal kingdom (1995) is the phylum Cycliophora. It includes three species of tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The body is sac-like and has a U-shaped intestine that brings the anus close to the mouth. Cycliophorans are coelomates, do not molt (though their host does), and their embryos undergo spiral cleavage. Cycliophorans have two types of larvae. One type of larva is produced when the digestive system of a female is impregnated by a male. The digestive system then collapses and develops into a larva, which swims away in search of a new host after the surrounding female dies. Which is the embryonic tissue that is apparently most important in forming this type of larva? A) mesohyl B) mesoderm C) ectoderm D) endoderm

D

The most recently discovered phylum in the animal kingdom (1995) is the phylum Cycliophora. It includes three species of tiny organisms that live in large numbers on the outsides of the mouthparts and appendages of lobsters. The feeding stage permanently attaches to the lobster via an adhesive disk and collects scraps of food from its host's feeding by capturing the scraps in a current created by a ring of cilia. The body is sac-like and has a U-shaped intestine that brings the anus close to the mouth. Cycliophorans are coelomates, do not molt (though their host does), and their embryos undergo spiral cleavage. Using similarities in embryonic development, body symmetry, and other anatomical features to assign an organism to a clade involves _____. 1. cladistics based on body plan 2. molecular-based phylogeny 3. morphology-based phylogeny A) 1 only B) 2 only C) 3 only D) 1 and 3

D

What do all deuterostomes have in common? A) Adults are bilaterally symmetrical. B) Embryos have pharyngeal pouches that may or may not form gill slits. C) All have a spinal column. D) The pore (blastopore) formed during gastrulation becomes the anus.

D

What do animals ranging from corals to monkeys have in common? A) a mouth and an anus B) number of embryonic tissue layers C) type of body symmetry D) presence of Hox genes

D

Which of the following would you classify as something other than an animal? A) sponges B) coral C) jellyfish D) choanoflagellates

D

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships? The fossil record reveals an increased incidence of _____. A) worm burrows B) larger animals C) organic material D) hard parts

D

You find a new species of worm and want to classify it. Which of the following lines of evidence would allow you to classify the worm as a nematode and not an annelid? A) It is segmented. B) It is triploblastic. C) It has a coelom. D) It sheds its external skeleton to grow.

D

You have before you a living organism, which you examine carefully. Which of the following should convince you that the organism is acoelomate? A) It is triploblastic. B) It has bilateral symmetry. C) It possesses sensory structures at its anterior end. D) Muscular activity of its digestive system distorts the body wall.

D

Members of the phylum Mollusca _____. A. are filter feeders B. have tentacles surrounding a central mouth/anus C. have closed circulatory systems D. are soft-bodied and often covered by a shell E. have segmented bodies and paired, jointed appendages

D. are soft-bodied and often covered by a shell

Which clade does not include humans? Which clade does not include humans? A. lobe-fins B. synapsids C. osteichthyans D. diapsids E. craniates

D. diapsids

During embryological development, the anus forms before the mouth in _____. During embryological development, the anus forms before the mouth in _____. A. earthworms B. arthropods C. flatworms D. humans E. slugs

D. humans

Gastrulation is the process that directly forms the _____. Gastrulation is the process that directly forms the _____. A. organs B. central nervous system C. blastula D. primary germ layers E. muscles

D. primary germ layers

What do lampreys, sharks, snakes, turtles, and cats have that a hagfish lacks? What do lampreys, sharks, snakes, turtles, and cats have that a hagfish lacks? A. a cranium B. jaws C. a notochord at some point in their lives D. vertebrae E. legs

D. vertebrae

The earliest ancestors of about half of all extant animal phyla can be traced back to the _____ explosion. The earliest ancestors of about half of all extant animal phyla can be traced back to the _____ explosion. A. Jurassic B. Devonian C. Pleistocene D. Carboniferous E. Cambrian

E. Cambrian

Which of the following is characteristic of the phylum Platyhelminthes? Which of the following is characteristic of the phylum Platyhelminthes? A. They are all parasitic. B. They typically reproduce asexually. C. They are radially symmetrical. D. They are diploblastic. E. They are dorsoventrally flattened.

E. They are dorsoventrally flattened.

Which of the following could be considered the most recent common ancestor of living tetrapods? A. an early terrestrial caecilian whose legless condition had evolved secondarily B. an early ray-finned fish that developed bony skeletal supports in its paired fins C. an armored, jawed placoderm with two pairs of appendages D. a salamander that had legs supported by a bony skeleton but moved with the side-to-side bending typical of fishes E. a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates

E. a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates

Which of the following is a characteristic of cnidarians? Which of the following is a characteristic of cnidarians? A. an anus B. bilateral symmetry C. mesoderm D. radula E. gastrovascular cavity

E. gastrovascular cavity

Which of these is a point of conflict between the phylogenetic analyses presented in Figures 32.10 and 32.11 in your textbook? Which of these is a point of conflict between the phylogenetic analyses presented in Figures 32.10 and 32.11 in your textbook? A. the monophyly of the bilaterians B. the monophyly of the animal kingdom C. that chordates are deuterostomes D. that sponges are basal animals E. the relationship of taxa of segmented animals to taxa of nonsegmented animals

E. the relationship of taxa of segmented animals to taxa of nonsegmented animals

A graduate student finds an organism in a pond and thinks it is a freshwater sponge. A postdoctoral student thinks it looks more like an aquatic fungus. How can they decide whether it is an animal or a fungus? Look for cell walls under a microscope. See if it reproduces sexually. Determine whether it is unicellular or multicellular. See if it is a eukaryote or prokaryote. Figure out whether it is autotrophic or heterotrophic.

Look for cell walls under a microscope. Fungal cells have cell walls, and animal cells do not.

You have before you a living organism, which you examine carefully. Which of the following should convince you that the organism is acoelomate? Muscular activity of its digestive system distorts the body wall. It possesses sensory structures at its anterior end. It is triploblastic. It has bilateral symmetry.

Muscular activity of its digestive system distorts the body wall.

Which of the following is NOT a characteristic of all animals? They are all multicellular. They ingest their food. They are eukaryotes. They are heterotrophic. They have tissues, organs, and organ systems.

They have tissues, organs, and organ systems. Sponges are considered animals, and they lack these levels of organization.

What is true of the deuterostomes in the molecular phylogeny (B) that is not true in the traditional phylogeny (A)? Deuterostomia now includes the Acoela. It diverged from the rest of the Bilateria earlier than did the Acoela. Deuterostomia is paraphyletic. To maintain Deuterostomia as a clade, some phyla had to be removed from it. It is actually a grade, rather than a clade.

To maintain Deuterostomia as a clade, some phyla had to be removed from it.

At which developmental stage should one be able to first distinguish a protostome embryo from a deuterostome embryo? gastrulation metamorphosis coelom formation fertilization cleavage

cleavage

Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If true, this finding would strengthen sponges' evolutionary ties to the Eumetazoa. mean that sponges must no longer be classified as animals. confirm the identity of sponges as "basal animals." mean that extinct sponges must have been the last common ancestor of animals and fungi. require sponges to be reclassified as choanoflagellates.

confirm the identity of sponges as "basal animals."

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 to lie in the grooves between larger, underlying cells (i.e., spiral cleavage). This embryo may potentially develop into a(n) earthworm. fish. sea urchin. turtle. sea star.

earthworm.

The last common ancestor of all animals was probably a multicellular algae. unicellular yeast. flagellated protist. unicellular chytrid. multicellular fungus.

flagellated protist.

Which of the following animals does NOT have a body cavity? nematode clam earthworm mouse flatworm

flatworm Flatworms are acoelomates, even those that are not classified as acoels.

An important trend in animal evolution was cephalization. An animal is said to show cephalization when it _____. has bilateral symmetry is large has tissue specialization has an aggregation of sensory neurons at the anterior end has a hard, outer covering

has an aggregation of sensory neurons at the anterior end Cephalization is an evolutionary trend toward the concentration of sensory equipment at the anterior end. It is associated with bilateral symmetry.

What distinguishes a coelomate animal from a pseudocoelomate animal is that coelomates have a complete digestive system with mouth and anus, whereas pseudocoelomates have a digestive tract with only one opening. have a body cavity, whereas pseudocoelomates have a solid body. have a gut that lacks suspension within the body cavity, whereas pseudocoelomates have mesenteries that hold the digestive system in place. contain tissues derived from mesoderm, whereas pseudocoelomates have no such tissue. have a body cavity completely lined by mesodermal tissue, whereas pseudocoelomates do not.

have a body cavity completely lined by mesodermal tissue, whereas pseudocoelomates do not.

During embryological development, the anus forms before the mouth in _____. slugs humans arthropods earthworms flatworms

humans During gastrulation, the developing digestive tube of the embryo initially has a single opening, the blastopore. After the archenteron develops, a second opening forms at the opposite end of the gastrula. The mouth of many protostomes develops from the first opening, whereas in deuterostomes the mouth is derived from the second opening.

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that only animals derive their nutrition by using enzymes to digest their food. consuming living, rather than dead, prey. ingesting it. preying on animals.

ingesting it.

If a multicellular animal lacks true tissues, then it can properly be included among the eumetazoans. choanoflagellates. lophotrochozoans. metazoans. bilateria.

metazoans.

Which of the following is (are) unique to animals? heterotrophy flagellated gametes cells that have mitochondria the structural carbohydrate, chitin nervous conduction and muscular movement

nervous conduction and muscular movement

Gastrulation is the process that directly forms the _____. blastula organs muscles primary germ layers central nervous system

primary germ layers

Which of the following is descriptive of protostomes? radial and determinate cleavage, blastopore becomes mouth spiral and determinate cleavage, blastopore becomes mouth spiral and indeterminate cleavage, blastopore becomes mouth radial and determinate cleavage, blastopore becomes anus spiral and determinate cleavage, blastopore becomes anus

spiral and determinate cleavage, blastopore becomes mouth

An adult animal that possesses bilateral symmetry is most certainly also triploblastic. eucoelomate. a deuterostome. highly cephalized.

triploblastic.

The most ancient branch point in animal phylogeny is that between having radial or bilateral symmetry. true tissues or no tissues. a well-defined head or no head. a body cavity or no body cavity. diploblastic or triploblastic embryos.

true tissues or no tissues.