Campbell Biology in Focus, 2e (Urry)
Chapter 27 The Rise of Animal Diversity
27.1 Multiple-Choice Questions
1) Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal
heterotrophy is that only animals derive their nutrition from
A) preying on animals.
B) ingesting it.
C) consuming living, rather than dead, prey.
D) using enzymes to digest their food.
2) Which of the following is (are) unique to animals?
A) cells that have mitochondria
B) the structural carbohydrate, chitin
C) nervous conduction and muscular movement
D) heterotrophy
E) flagellated gametes
3) In terms of food capture, which sponge cell is most similar to the cnidocyte of a cnidarian?
A) amoebocyte
B) choanocyte
C) epidermal cell
D) gastrovascular cavity cell
4) Sponges are most accurately described as
A) marine predators.
B) chemoautotrophs.
C) freshwater scavengers.
D) filter feeders.
E) aquatic predators.
5) Which of the following functions as both a mouth and an anus in members of the phylum
Cnidaria?
A) a noncentralized nerve net
B) a gastrovascular cavity
C) nematocysts
D) an alimentary canal
6) Which of the following is true of members of the phylum Cnidaria?
A) They are not capable of locomotion because they lack true muscle tissue.
B) They are primarily filter feeders.
C) They coordinate movements through a noncentralized nerve set.
D) They are the simplest organisms with a complete alimentary canal (two openings).
7) The members of which clade in the phylum Cnidaria occur only as polyps?
A) Hydrozoa
B) Scyphozoa
C) Anthozoa
D) Arthropoda
8) The last common ancestor of all animals was probably a(n)
A) chytrid.
B) yeast.
C) algae.
D) fungus.
E) protist.
9) Evidence of which structure or characteristic would be most surprising to find among fossils
of the Ediacaran fauna?
A) true tissues
B) hard body parts
C) bilateral symmetry
D) embryos
10) The most ancient branch point in animal phylogeny is that between having
A) radial and bilateral symmetry.
B) a well-defined head and no head.
C) true tissues and no tissues.
D) a body cavity and no body cavity.
11) According to the evidence collected so far, the animal kingdom is
A) monophyletic.
B) paraphyletic.
C) no longer growing in size.
D) growing at an exponential rate.
12) If a multicellular animal lacks true tissues, then it can properly be included among the
A) eumetazoans.
B) metazoans.
C) choanoflagellates.
D) lophotrochozoans.
E) bilateria.
13) 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 only
B) 1 and 3
C) 3 and 5
D) 3, 4, and 5
14) 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 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.
E) Only phylogenies based solely on fossil evidence will need to be discarded.
15) Some researchers claim that sponge genomes have homeotic genes (genes that regulate
development of anatomical structures), but no Hox genes (genes that regulate development of
posterior-anterior axes and body segments). If true, this finding would
A) strengthen sponges’ evolutionary ties to the Eumetazoa.
B) mean that sponges must no longer be classified as animals.
C) confirm the identity of sponges as basal animals.
D) mean that extinct sponges must have been the last common ancestor of animals and fungi.
E) require sponges to be reclassified as choanoflagellates.
16) The last common ancestor of all bilaterians is thought to have had four Hox genes (genes that
regulate development of posterior-anterior axes and body segments). Most extant cnidarians have
two Hox genes, except Nematostella, 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) 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) Cnidaria may someday replace porifera as the basal bilaterians.
E) Cnidarians are the basal metazoans.
17) 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 hard body parts in the fossil record
18) 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.
19) 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
20) 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
21) Which of the following genetic processes may be most helpful in accounting for the
Cambrian explosion?
A) binary fission
B) mitosis
C) meiosis
D) gene duplication
22) 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 are diploblastic.
4. All cnidarians are acoelomate.
A) 1 only
B) 1 and 4 only
C) 2 and 3 only
D) 2 and 4 only
E) 3 and 4 only
23) Which of the following animal groups is entirely aquatic?
A) Mollusca
B) Crustacea
C) Echinodermata
D) Nematoda
E) Platyhelminthes
24) Chordate pharyngeal slits appear to have functioned first as
A) the digestive system’s opening.
B) suspension-feeding devices.
C) components of the jaw.
D) gill slits for respiration.
E) portions of the inner ear.
25) Which of the following statements would be least acceptable to most zoologists?
A) The extant lancelets are contemporaries, not ancestors, of vertebrates.
B) The first fossils resembling lancelets appeared in the fossil record around 530 million years
ago.
C) Recent work in molecular systematics supports the hypothesis that lancelets are the basal
clade of chordates.
D) The extant lancelets are the immediate ancestors of the fishes.
E) Lancelets display the same method of swimming as do fishes.
26) Which extant chordates are postulated to be most like the earliest chordates in physical
appearance?
A) lancelets
B) adult tunicates
C) amphibians
D) reptiles
E) chondrichthyans
27) A new species of aquatic chordate is discovered that closely resembles an ancient form. It
has the following characteristics: external armor of bony plates, no paired lateral fins, and a
suspension-feeding mode of nutrition. In addition to these, it will probably have which of the
following characteristics?
A) legs
B) no jaws
C) an amniotic egg
D) endothermy
28) What do all craniates have that earlier chordates did not have?
A) brain
B) vertebrae
C) cartilaginous pipe surrounding notochord
D) partial or complete skull
E) bones
29) The feeding mode of the extinct conodonts was
A) herbivory.
B) suspension feeding.
C) predation.
D) filter feeding.
E) absorptive feeding.
30) The earliest known mineralized structures in vertebrates are associated with which function?
A) reproduction
B) feeding
C) locomotion
D) defense
E) respiration
31) Jaws first occurred in which extant group of fishes?
A) lampreys
B) chondrichthyans
C) ray-finned fishes
D) lungfishes
E) placoderms
32) Which of these might have been observed in the common ancestor of chondrichthyans and
osteichthyans?
A) a mineralized, bony skeleton
B) limbs
C) digits
D) a swim bladder
33) Which group’s members have had both lungs and gills during their adult lives?
A) sharks, skates, and rays
B) lungfishes
C) lancelets
D) bivalves
34) Which of the following belong to the lobe-fin clade?
A) chondrichthyans
B) ray-finned fishes
C) lampreys
D) hagfishes
E) tetrapods
35) Arrange these taxonomic terms from most inclusive (most general) to least inclusive (most
specific).
1. lobe-fins
2. amphibians
3. gnathostomes
4. osteichthyans
5. tetrapods
A) 4, 3, 1, 5, 2
B) 4, 3, 2, 5, 1
C) 4, 2, 3, 5, 1
D) 3, 4, 1, 5, 2
E) 3, 4, 5, 1, 2
36) During chordate evolution, what is the sequence (from earliest to most recent) in which the
following structures arose?
1. amniotic egg
2. paired fins
3. jaws
4. four-chambered heart
A) 2, 3, 1, 4
B) 3, 2, 1, 4
C) 4, 1, 3, 2
D) 2, 1, 3, 4
E) 1, 3, 2, 4
37) Which of the following are the most abundant and diverse of the extant vertebrates?
A) ray-finned fishes
B) birds
C) amphibians
D) mammals
38) What should be true of fossils of the earliest tetrapods?
A) They should show evidence of internal fertilization.
B) They should show evidence of having produced shelled eggs.
C) They should indicate limited adaptation to life on land.
D) They should be transitional forms with the fossils of chondrichthyans that lived at the same
time.
E) They should feature the earliest indications of the appearance of jaws.
39) Which of these are amniotes?
A) amphibians
B) fishes
C) mammals
D) placental mammals only
E) egg-laying mammals only
40) Why is the amniotic egg considered an important evolutionary breakthrough?
A) It has a shell that increases gas exchange.
B) It allows deposition of eggs in a terrestrial environment.
C) It prolongs embryonic development.
D) It provides insulation to conserve heat.
E) It permits internal fertilization to be replaced by external fertilization.
41) Which of these characteristics added most to vertebrate success in relatively dry
environments?
A) the shelled, amniotic egg
B) the ability to maintain a constant body temperature
C) two pairs of appendages
D) bony scales
E) a four-chambered heart
42) Which of the following are the only extant animals that descended directly from dinosaurs?
A) lizards
B) crocodiles
C) snakes
D) birds
E) tuataras
43) A trend first observed in the evolution of the earliest tetrapods was
A) the appearance of jaws.
B) the appearance of bony vertebrae.
C) feet with digits.
D) the mineralization of the endoskeleton.
E) the amniotic egg.
44) Among the invertebrate phyla, phylum Arthropoda is unique in possessing members that
have
A) a cuticle.
B) a ventral nerve cord.
C) open circulation.
D) wings.
E) segmented bodies.
45) 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) ancestral arthropods must have been poorly adapted to aquatic life and thus experienced a
selective pressure to invade land.
D) vertebrates evolved from arthropods.
E) arthropods have had more time to coevolve with land plants than vertebrates have had.
46) Which of these would a paleontologist be most likely to do in order to determine whether a
fossil represents a reptile or a mammal?
A) Look for the presence of milk-producing glands.
B) Look for the mammalian characteristics of a four-chambered heart and a diaphragm.
C) Because mammals are eutherians, look for evidence of a placenta.
D) Use molecular analysis to look for the protein keratin.
E) Examine the teeth to determine how sharp or ground down they are.
47) In which vertebrates is fertilization exclusively internal?
A) chondrichthyans, osteichthyans, and mammals
B) amphibians, mammals, and reptiles
C) chondrichthyans, osteichthyans, and reptiles
D) reptiles and mammals
E) reptiles and amphibians
48) Internal fertilization, leathery amniotic eggs, and skin that resists drying are characteristics of
which extant vertebrate group?
A) amphibians
B) non-bird reptiles
C) chondrichthyans
D) mammals
E) birds.
49) Organisms at which of the following trophic levels increased the most because of the
movement of animals onto land?
A) herbivores and carnivores
B) decomposers and producers
C) producers
D) decomposers
50) The decline of cyanobacteria in the early Cambrian oceans was most likely related to
A) the movement of animals onto land.
B) the evolution of land plants.
C) an increase in the number of predatory fish.
D) an increase in organisms with suspension-feeding mouthparts.
E) a decline in the number of marine decomposers.
51) If all of the animals died in a large region of an ocean, we would expect an increase in the
A) number of filter feeders.
B) number of cyanobacteria.
C) number of decomposers.
D) clarity of the ocean waters.
E) temperature of the ocean waters.
52) Evidence indicates that an ancestral finch species from South America arrived on the
Galapágos Islands and formed many new species, adapting to the diverse environments on the
islands. With the evolution of these new bird species on the Galapágos Islands, we would expect
to find a corresponding
A) increase in the number of bird parasites on the Galapágos Islands.
B) decrease in the number of bird parasites on the Galapágos Islands.
C) increase in the number of bird parasites in South America.
D) decrease in the number of bird parasites in South America.
E) elimination of bird parasites on the Galapágos Islands.
53) A new, sixth global mass-extinction event appears to be occurring on Earth today. The most
likely explanation for the dramatic loss of species is
A) climate change.
B) natural fluctuations in global temperatures and precipitation.
C) the evolution of new types of viruses.
D) human activity that alters natural environments.
E) decreases in atmospheric levels of oxygen.
54) As a result of harvesting a higher proportion of older and larger cod and other fish species for
food,
A) the number of fish in these populations has increased dramatically.
B) the age and size of fish reaching sexual maturity have decreased.
C) many new species of predators have evolved in these regions.
D) the affected fish species have stopped reproducing.
E) many of the fish in these populations have started to reproduce asexually.
55) Which of the following characteristics distinguishes modern humans from other modern
apes?
1. Humans walk upright.
2. Humans walk on two legs.
3. Humans use simple tools.
4. Humans are capable of symbolic thought.
A) 2 and 3 only
B) 1, 2 and 4 only
C) 2, 3, and 4 only
D) 1, 2, 3, and 4 only
56) What is a primary, common evolutionary feature of all reptiles, mammals, and birds?
A) teeth
B) endothermic behavior
C) gastrovascular cavity
D) amniotic egg
57) One important evolutionary change that occurred with the rise of animals is
A) a change from a microbe-only environment to one of large producers, predators, and prey.
B) the extinction of cyanobacteria.
C) a marine ecosystem dominance of sponges and cnidarians.
D) a confirmed second common ancestor of animals.
58) If wild dogs take part in cooperative hunting, they will likely have a better outcome than if
they hunt alone, especially if they share the prey. The dogs that cooperate are increasing the
survival probability of one another. This is an example of
A) parasitism.
B) reciprocal selection.
C) defensive adaptations.
D) adaptive radiation.
59) Humans widely use pesticides on plants as a means to control insect and plant pests.
However, pesticides are not selective in what they kill, so they often kill beneficial insect and
plant species as well. This unintentional consequence favors plant and insect species that are
pesticide resistant. This scenario is an example of
A) human impacts on evolution.
B) reciprocal selection.
C) human impacts on antibiotic resistance.
D) mass extinction of plant species.
60) A student catches a ray-finned fish from the ocean and notices that attached to its flank is an
equally long, snakelike organism. The attached organism has no external segmentation, no
scales, a slimy substance on its surface, a round mouth surrounded by a sucker, a tongue, and
two small eyes. The student thinks it might be a marine hagfish or a lamprey. Which feature
excludes the organism from possibly being a lamprey?
A) elongated shape
B) lack of scales
C) a slimy substance on its surface
D) round mouth
E) tongue