Test 3 testbank Flashcards
Which of the following terms or structures is properly associated only with animals?
Hox genes
The number of legs an insect has, 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
Hox genes.
The last common ancestor of all animals was probably a
E) flagellated protist.
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.
Which statement is most consistent with the hypothesis that the Cambrian explosion was
caused by the rise of predator-prey relationships?
E) increased incidence of hard parts in the fossil record
Which of the following was the least likely factor causing the Cambrian explosion?
C) the movement of animals onto land
11) Evidence of which structure or characteristic would be most surprising to find among
fossils of the Ediacaran fauna?
B) hard parts
Which of these genetic processes may be most helpful in accounting for the Cambrian
D) gene duplication
Organisms showing radial symmetry would likely
C) move from place to place relatively slowly, if at all.
During metamorphosis, echinoderms undergo a transformation from motile larvae to a
sedentary (or sometimes sessile) existence as adults. What differentiates echinoderm adults,
but not their larvae? Adults should
B) have radial symmetry, or something close to it.
An adult animal that possesses bilateral symmetry is most certainly also
A) triploblastic.
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
D) sponge.
Some researchers claim that sponge genomes have homeotic genes, but no Hox genes. If
true, this finding would
C) confirm the identity of sponges as ʺbasal animals.ʺ
The distinction between sponges and other animal phyla is based mainly on the absence
versus the presence of
D) true tissues.
Which cells in a sponge are primarily responsible for trapping and removing food particles
from circulating water?
A) choanocytes
A spongeʹs structural materials (spicules, spongin) are manufactured by the
amoebocytes.
Which chemical is synthesized by some sponges and acts as an antibiotic?
E) cribrostatin
In terms of food capture, which sponge cell is most similar to the cnidocyte of a Cnidarian?
B) choanocyte
Which group contains diploblastic organisms?
A) I
Which group consists of deuterostomes?
B) II
The blastopore is a structure that first becomes evident during
B) gastrulation.
Which of the following is descriptive of protostomes?
B) spiral and determinate cleavage, blastopore becomes mouth
Protostomes that have an open circulatory system and an exoskeleton of chitin are part of
which phylum?
D) Arthropoda
Protostomes with a unique drape of tissue that may secrete a shell are part of which
phylum?
C) Mollusca
Which of the following organisms are deuterostomes?
C) echinoderms
D) chordates
E) both C and D
Deuterostomes that have an endoskeleton are part of which phylum?
E) Echinodermata
What is characteristic of all ecdysozoans?
B) some kind of exoskeleton, or hard outer covering
Which of the following was the least likely factor causing the Cambrian explosion?
the movement of animals onto land
Which cells in a sponge are primarily responsible for trapping and removing food particles
from circulating water?
A) choanocytes
In terms of food capture, which sponge cell is most similar to the cnidocyte of a Cnidarian?
B) choanocyte
A radially symmetrical animal that has two embryonic tissue layers probably belongs to
which phylum?
B) Cnidaria
9) Which of the following are characteristics of the phylum Cnidaria?
1. a gastrovascular cavity
2. a polyp stage
3. a medusa stage
4. cnidocytes
5. a pseudocoelom
D) 1, 2, 3, and 4
Which of the following is true of members of the phylum Cnidaria?
D) They may use a gastrovascular cavity as a hydrostatic skeleton.
The members of which class of the phylum Cnidaria occur only as polyps?
C) Anthozoa
Which class of the phylum Cnidaria includes ʺjelliesʺ with rounded (as opposed to boxlike) medusae?
B) Scyphozoa
Which characteristic is shared by both cnidarians and flatworms?
D) a digestive system with a single opening
A stalked, sessile marine organism has several feathery feeding structures surrounding an
opening through which food enters. The organism could potentially be a cnidarian, a
lophophorate, a tube-dwelling worm, a crustacean, or an echinoderm. Finding which of the
following in this organism would allow the greatest certainty of identification?
D) a water vascular system
Which of the following is a diploblastic phylum of aquatic predators?
A) Cnidaria
Generally, members of which flatworm class(es) are nonparasitic?
A) Turbellaria
While vacationing in a country that lacks adequate meat inspection, a student ate
undercooked ground beef. Sometime later the student became easily fatigued, and lost
body weight. At about the same time, whitish, flattened, rectangular objects full of small
white spheres started appearing in his feces. Administration of niclosamide cured the
problem. The student had probably been infected by a
D) tapeworm.
20) Which of the following correctly characterizes the phylum Rotifera?
C) parthenogenic reproduction
While sampling marine plankton in a lab, a student encounters large numbers of fertilized
eggs. The studentrears some of the eggs in the laboratory forfurther study and finds that
the blastopore becomes the mouth. The embryo develops into a trochophore larva and
eventually has a true coelom. These eggs probably belonged to a(n)
C) mollusc.
A radula is present in members of which class(es)?
C) gastropods
An organism is able to extend its feeding structure(s) through a hole in its body wall. If the
organism were a sea star, it would extend its
A) stomach.
If the teacher wanted to show the students what a lophophore is, and how it works, the
teacher would point out a feeding
E) ectoproct.
A lophophore is used by ectoprocts and brachiopods
C) for feeding.
) Which molluscan class includes members that undergo embryonic torsion?
D) cephalopods
A land snail, a clam, and an octopus all share
A) a mantle.
A brachiopod can be distinguished from a bivalve by the presence of
C) a lophophore.
While snorkeling, a student observes an active marine animal that has a series of muscular
tentacles bearing suckers associated with its head. Segmentation is not observed, but a pair
of large, well-developed eyes is evident. The student is observing an animal belonging to
which class?
B) bivalves
Which molluscan class includes organisms that are primarily suspension feeders?
B) bivalves
Some species of which of the following annelid classes release an anticoagulant that is of
medical significance?
C) Hirudinea (leeches)
Which of the following is a characteristic of nematodes?
B) They have only longitudinal muscles.
Which of the following can be used to distinguish a nematode worm from an annelid
worm?
1. type of body cavity
2. number of muscle layers in the body wall
3. presence of segmentation
4. number of embryonic tissue layers
5. shape of worm in cross-sectional view
C) 1, 2, and 3
Nematode worms and annelid worms share which of the following features?
A) use of fluid in the body cavity as a hydrostatic skeleton
The heartworms that can accumulate within the hearts of dogs and other mammals have a
pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To
which phylum does the heartworm belong?
C) Nematoda
Which of the following are characteristics of arthropods?
- protostome development
- bilateral symmetry
- a pseudocoelom
- three embryonic germ layers
- a closed circulatory system
C) 1, 2, and 4
Among the invertebrate phyla, phylum Arthropoda is unique in possessing members that
have
D) wings.
A shared derived characteristic for members of the arthropod subgroup that includes
spiders would be the presence of
A) chelicerae.
Protostomes that have an open circulatory system and an exoskeleton of chitin are part of
which phylum?
D) Arthropoda
Which of the following is a steroid hormone that triggers molting in arthropods?
A) ecdysone
You find a small animal with eight legs crawling up your bedroom wall. Closer
examination will probably reveal that this animal has
B) no antennae.
C) chelicerae.
E) B and C
While working in your garden, you discover a worm-like, segmented animal with two
pairs of jointed legs per segment. The animal is probably a
A) millipede.
Sarah noticed the presence of many empty exoskeletons attached to emergent vegetation.
These exoskeletons looked exactly like those of the largest of the ʺmystery organismsʺ she
had seen in the pond. They also looked similar to the bodies of the dragonflies that
patrolled the surface of the pond. If Sarah had learned a lot from her college biology class,
what should she have concluded about the mysterious pond organisms?
A) They are larval dragonflies, destined to undergo incomplete metamorphosis.
What distinguishes complete metamorphosis from incomplete metamorphosis in insects?
C) radically different appearance between adults and earlier life stages
The possession of two pairs of antennae is a characteristic of
E) crustaceans.
Sarah had learned that ancestral (Carboniferous era) dragonfly species were much larger
than extant dragonfly species are, with wingspans of 70 cm. This struck her as odd, because
she had also learned that one of the things that keeps insects small is their relatively
inefficient respiratory system. Which two hypotheses might help account for the large size
of ancestral dragonflies?
1. If the atmosphere during the Carboniferous had featured a higher oxygen content than
the modern atmosphere, then tracheae might have been sufficient means for oxygen
delivery to the interior tissues.
2. If large size was a drawback, then the large dragonflies underwent extinction, which
explains why all extant dragonflies are smaller.
3. If the ancestral dragonflies had possessed muscles that permitted effective ventilation of
the tracheae, then the tracheae might have been sufficient means for oxygen delivery to the
interior tissues.
4. If ancestral dragonflies existed during greenhouse conditions, then they must have
survived by decreasing their activity levels, no longer capturing prey in flight. Thus, for
them, an ineffective respiratory system was sufficient.
A) 1 and 2
Which of the following is a characteristic of adult echinoderms?
A) secondary radial symmetry
Which of the following describe(s) echinoderms?
A) They have an endoskeleton of hard calcareous plates.
B) Tube feet provide motility in most species.
D) Only A and B are true.
A stalked, sessile marine organism has several feathery feeding structures surrounding an
opening through which food enters. The organism could potentially be a cnidarian, a
lophophorate, a tube-dwelling worm, a crustacean, or an echinoderm. Finding which of the
following in this organism would allow the greatest certainty of identification?
D) a water vascular system
Which of the following animal groups is entirely aquatic?
C) Echinodermata
Deuterostomes that have an endoskeleton are part of which phylum?
E) Echinodermata
The water vascular system of echinoderms
B) functions in locomotion, feeding, and gas exchange.
Which of the following is a shared characteristic of all chordates?
D) dorsal, hollow nerve cord
) Which of these are characteristics of all chordates during at least a portion of their
development?
A) a dorsal, hollow nerve cord
B) pharyngeal clefts
C) post-anal tail
E) A, B, and C
Chordate pharyngeal slits appear to have functioned first as
B) suspension-feeding devices.
According to one hypothesis, the jaws of vertebrates were derived by the modification of
B) skeletal rods that had supported pharyngeal (gill) slits.
Which of the following statements would be least acceptable to most zoologists?
D) The extant cephalochordates are the immediate ancestors of the fishes.
What do hagfishes and lampreys have in common with the extinct conodonts?
B) the jawless condition
In which of these extant classes did jaws occur earliest?
B) chondrichthyans
Which extant chordates are postulated to be mostlike the earliest chordates in appearance?
A) lancelets
What is a distinctive feature of the chondrichthyans?
D) a mostly cartilaginous endoskeleton
To which of these are the scales of chondrichthyans most closely related in a structural
sense?
E) chondrichthyan teeth
There is evidence that ray-finned fishes originally evolved
E) in freshwater environments.
Which of these statements accurately describes a similarity between sharks and ray-finned
fishes?
D) They have a lateral line that is sensitive to changes in water pressure.
The ray-finned fishes are characterized by
A) a bony endoskeleton, operculum, and usually a swim bladder.
The swim bladder of ray-finned fishes
A) was probably modified from simple lungs of freshwater fishes.
Which are the most abundant and diverse of the extant vertebrates?
A) ray-finned fishes
6) Which clade does not include humans?
C) diapsids
Why is the amniotic egg considered an important evolutionary breakthrough?
B) It allows incubation of eggs in a terrestrial environment.
Which of these characteristics added most to vertebrate success in relatively dry
environments?
A) the amniotic egg
Most dinosaurs and pterosaurs become extinct at the close of the __________ era.
A) Cretaceous
Which of these is not considered an amniote?
A) amphibians
Which of the following structures are possessed only by birds?
C) feathers and keeled sternum
Examination of the fossils of Archaeopteryx reveals that, in common with extant birds, it had
B) feathers.
Why is the discovery of the fossil Archaeopteryx significant? It supports the
A) phylogenetic relatedness of birds and reptiles.
Which groupʹs members had (have) both lungs and gills during their adult lives?
B) lungfishes
Whose DNA would have had the most sequence homologies with amphibian DNA?
E) 9
Which pair of numbers includes extant endotherms?
C) 6 and 8
Among extant vertebrates, a sheet of muscle called the diaphragm is found in
B) mammals.
Which of these would a paleontologist be most likely to do in order to determine whether a
fossil represents a reptile or a mammal?
E) Examine the teeth.
Which of the following is characteristic of most extant reptiles and most extant mammals?
D) keratinized skin
Which of the following statements is correct in regard to Homo erectus?
Their fossils are not limited to Africa.
Three major groups: egg-laying, pouched, and placental
D) mammals
May have lungs, or gills, and may use skin as a respiratory surface
A) amphibians
Which of these traits is most strongly associated with the adoption of bipedalism?
repositioning of foramen magnum
Which term is most nearly synonymous with ʺapesʺ?
A) hominoids
Which is the most specific group in which prosimians can be included?
E) primates
This is a cluster of genes coding for transcription factors involved in the evolution of
innovations in early vertebrate nervous systems and vertebrae:
B) Dlx
This is a gene linked to the development of speech in hominids:
D) FOXP2
