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Multiple choice type questions
1. Which of the following characteristics distinguishes Parazoans from Protozoans?
A. Intracellular digestion.
B. Multicellularity.
C. The absence of cell walls.
D. The absence of tissues.
E. Both B and D are characteristic of Parazoans but not Protozoans.
2. A variety of factors contributes significantly to the ability of aquatic mammals to maintain their ideal
body temperature, including:
A. Large body size
B. Resting metabolic rates that are approximately 2x higher than would be expected on the basis of
body size alone
C. Blubber
D. Counter-current heat exchangers in the flippers
E. All of the above contribute significantly to the ability of aquatic mammals to maintain their ideal
body temperature.
3. The figure at right depicts
A. an omnivorous suspension feeder
B. a herbivorous substrate feeder
C. a detritovorous deposit feeder
D. a parasitic fluid feeder
E. a carnivorous bulk feeder
(Campbell & Reece 2002)
4. Which of the following utilises an open hydrostatic skeleton to generate the motion required for feeding?
A. Chameleon
B. Sea anemone
C. Sponge
D. C. elegans
E. All of the above make use of an open hydrostatic skeleton in feeding.
5. In golden toads, Bufo periglenes, the female is mainly black with yellow and red markings, whereas the
male is bright orange. A reasonable explanation for the vivid coloration of the males is that…
A. It probably evolved through natural selection as a warning signal to potential predators that this
species of toad is poisonous.
B. This species of toad feeds on plants containing high concentrations of carotenoids which are
subsequently deposited in the skin.
C. It represents a balance between the evolutionary selective forces of female choice and predation
pressure.
D. Females prefer brightly coloured males and natural selection has therefore acted to enhance male
coloration.
E. None of A, B, C, or D is a reasonable explanation for the vivid coloration of male golden toads.
6. A flea can jump a height 50 times greater than its body length, while human Olympic high-jumpers clear
heights that are only just taller than themselves. Why?
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A. Because of structural differences between arthropod and vertebrate muscles, the force generated
per unit area is greater for flea muscles than for human muscles.
B. Muscle mass scales disproportionately slowly in relation to body weight such that smaller animals
contain relatively more muscle mass than larger animals.
C. The margin of safety for skeletal breakage is greater in smaller animals than in larger animals and
therefore larger animals simply cannot afford to jump as high (relative to body height) as smaller
animals.
D. Muscle strength increases less rapidly with size than does body weight, so larger animals are not
as strong relative to their body weight as are smaller animals.
E. All of A, B, C and D are true and help to explain why fleas can jump so much higher than humans
in relation to their body size.
7. A mouse moves under a bush on a still, cold, clear fall night to reduce the rate at which it loses heat by:
A. Radiation
B. Evaporation
C. Conduction
D. Convection
E. Both A and B
8. The figure at right depicts heart rate in the Galapagos marine
iguana, Amblyrhynchus cristatus, over a period of 60 min.
During this period, the animal both entered and emerged from
the water. At what time (approximately) did the animal emerge
from the water?
A. 5 min
B. 10 min
C. 35 min
D. 40 min
E. The iguana remained submerged throughout the entire 60
min period.
(Bartholomew & Lasiewski 1965)
9. Which of the following features of the skeletal system of vertebrates would have facilitated the evolution
of large body size in dinosaurs?
A. Skeletal mass occupies a larger proportion of the body mass in large vertebrates than in small
vertebrates.
B. Increasing bone length has much less effect on bone strength than does increasing bone crosssectional area.
C. The density of the minerals in the bones of the vertebrate endoskeleton is greater than the density
of chitin, a key component of the arthropod exoskeleton.
D. Positioning bones under the centre of gravity makes use of the ability of bones to resist
compressive forces in supporting the body.
E. None of A, B, C or D were important in the evolution of large body size in dinosaurs.
10. Which of the following are characteristic of Deuterostomes but not Protostomes?
A. Determinate egg cleavage, enterocoelous coelom formation, ventral heart
B. Radial egg cleavage, exoskeleton, ventral nerve cord
C. Dorsal heart, schizocoelous coelom formation, spiral egg cleavage
D. Dorsal nerve cord, endoskeleton, indeterminate egg cleavage
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E. None of A, B, C or D could be used to distinguish a Deuterostome from a Protostome.
11. The rate of O2 uptake by a fish would be negatively impacted by:
A. Increasing the thickness of the gill epithelium.
B. Increasing ventilation (i.e. the rate at which water next to the gill is refreshed).
C. Increasing the surface area of the gills.
D. Increasing the partial pressure of O2 in the blood of the fish.
E. Both A and D would negatively impact the rate of O2 uptake by a fish.
12. Which of the following statements is true of the chameleon tongue, but not of the human tongue?
A. It is a muscular hydrostat.
B. Tension generation is proportional to the number of myosin crossbridges attached to the actin thin
filaments, and hence is proportional to the degree of overlap of the thick and thin filaments.
C. Limitations on the shortening of an individual sarcomere are overcome by the presence of
perforated Z-discs.
D. The actin and myosin filaments are arranged in nearly crystalline arrays such that a regular pattern
of bands, or striations, is visible.
E. All of the above statements are true of both the chameleon and human tongues.
13. Which of the following structures in an adult chicken is not derived from the embryonic ectoderm?
A. Nervous system
B. Muscle
C. Feathers
D. Lining of the anus
E. All of the above arise from the ectoderm germ layer of the developing embryo.
14. The fold increase in metabolic rate (VO2) experienced by a python that has just consumed a very large
meal (a meal equivalent to 100% of body mass, which is not unusual for these animals) is
approximately equivalent in magnitude to that of:
A. a racehorse galloping at top speed (45x increase in VO2)
B. a human sprinting at top speed for 10 s (18x increase in VO2)
C. a snake slithering at its top speed of 0.5 km h-1 (6x increase in VO2)
D. a trout digesting a large meal (2x increase in VO2)
E. a mink digesting a large meal (1.2x increase in VO2)
15. What is the most successful phylum as evidenced by the number of species it contains?
A. Chordata
B. Mollusca
C. Nematoda
D. Arthropoda
E. None of the above
16. Swimming and flying animals both undertake locomotion in a fluid environment and therefore face
similar problems. Which of the following solutions to these problems is not available to animals that fly?
A. Reduction in the density of the animal so as to achieve a match between the weight of the animal
and the weight of the fluid it displaces.
B. Combating the force of gravity through the generation of an upward force by creating a pressure
differential across a specially-shaped surface.
C. Generation of thrust to combat drag by accelerating the fluid in the direction opposite to that of
movement using specially-shaped surfaces.
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D. Increase in the cross-sectional area of the animal to decrease the rate at which the animal falls
vertically through the fluid.
E. All of A, B, C and D are available to both animals that fly and animals that swim.
17. In mammals, the developing embryo obtains O2 from its mother’s blood via the placenta. For this to
occur,
A. The foetal haemoglobin must have a higher P50 than the maternal haemoglobin.
B. The O2 equilibrium curve of the foetal haemoglobin must be left-shifted with respect to the curve for
the maternal haemoglobin.
C. The maternal haemoglobin must have a higher O2 binding affinity than the foetal haemoglobin.
D. The partial pressure of O2 at which the maternal haemoglobin is 50% saturated with O2 must be
lower than the corresponding value for the foetal haemoglobin.
E. Both A and D must be true.
18. Structural adaptations that may be present in the gastrointestinal tract to facilitate its function include
A. a crop
B. a gizzard
C. a typhlosole
D. sacculations
E. All of the above are structural adaptations that may be found in the gastrointestinal tract to facilitate
its function.
19. Which of the following are characteristic of the adductor muscle of bivalve molluscs?
A. It contains low levels of the O2-storing protein myoglobin and is innervated by a single nerve that
contacts the muscle fibre at several points and which must be fired repeatedly to elicit a complete
contraction.
B. It contains both striated and smooth muscle fibres that are innervated by excitatory nerves, and
excitatory plus inhibitory nerves, respectively.
C. It is innervated by 3 types of nerves: a fast nerve for rapid closing, a slow nerve for sustained
closing during air exposure or attacks from a predator, and an inhibitory nerve that modifies the
response of the muscle fibres to the fast and slow nerves.
D. It consists solely of striated muscle fibres that contain high levels of myoglobin and that are
innervated by a single nerve that contacts each muscle fibre only once.
E. None of A, B, C or D are characteristic of the adductor muscle of bivalve molluscs.
20. The figure at right depicts muscle temperature in tuna as a
function of water temperature. The heat that elevates muscle
temperature is a by-product of the metabolic activity that
supports swimming. On the basis of this information, the tuna is
best described as an:
A. ectothermic poikilotherm
B. endothermic homeotherm
C. endothermic poikilotherm
D. ectothermic homeotherm
E. None of the above adequately describes the thermal
strategy of the tuna.
(Randall et al. 2002)
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21. You are wandering through a patch of milkweed when you observe an adult monarch butterfly emerging
from its chrysalis. Which of the following predictions about hormone levels in the haemolymph of the
emerging adult is most likely to be correct?
A. The concentrations of both juvenile hormone and ecdysone are likely to be high.
B. The concentrations of both juvenile hormone and molt-inhibiting hormone are likely to be low.
C. A low concentration of juvenile hormone together with a high concentration of ecdysone is likely.
D. A high concentration of juvenile hormone together with a low concentration of molt-inhibiting
hormone is likely.
E. None of A, B, C or D are likely to be accurate predictions of the hormone levels in an adult
monarch butterfly emerging from its chrysalis.
22. The marine environment is a desert to some organisms, despite its aquatic nature. For which of the
following organisms is this statement true?
A. Dogfish
B. Lobster
C. Hagfish
D. Toadfish
E. The ocean is a desert for all of A, C and D.
23. The density of freshwater is 1.000 g mL-1 and the density of air is 0.001 g mL-1. The buoyant force
supporting a shark of volume 5 L will therefore be:
A. 5 times greater in water than in air.
B. 5000 times less in air than in water.
C. 10-fold greater in water than in air.
D. 1000-fold less in air than in water.
E. None of the above
24. Terrestrial insects are capable of achieving high metabolic rates (e.g. during flight) despite their low
pressure, open circulatory system primarily because of:
A. Their small size.
B. The high O2 affinity of their respiratory pigment.
C. Their extensive reliance on anaerobic metabolism.
D. Their use of a tracheal system for gas exchange.
E. All of A, B, C and D contribute to the ability of terrestrial insects to achieve high metabolic rates
despite their low pressure, open circulatory system.
25. It is harder for a kangaroo rat to maintain its body temperature (when the environmental temperature is
lower than the ideal body temperature) than it is for a kangaroo because:
A. Metabolic rate and SA:V ratio both increase with increasing size
B. Mass-specific metabolic rate and SA:V ratio both decrease with increasing size
C. Mass-specific metabolic rate and SA:V ratio both decrease with decreasing size
D. Metabolic rate and SA:V ratio both increase with decreasing size
E. None of the above adequately explains why it is harder for the kangaroo rat than the kangaroo to
maintain its body temperature
26. Obligate water-breathing fish, such as rainbow trout, suffocate if removed from the water because
A. The solubility of O2 in water is 30x higher than in air, so O2 is less available in air than in water.
B. The diffusion gradient for O2 across the gas exchange surface is unfavourable in air.
C. The O2 demand for metabolism increases in air beyond the capacity of the gas exchange system to
deliver O2.
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D. The collapse of the gills in a non-buoyant medium dramatically decreases the surface area for gas
exchange.
E. All of the above contribute to the problems experienced by obligate water-breathers in air.
27. Haemoglobin A. Is abundant in all vertebrates, without exception.
B. Consists of a globin protein in association with 4 copper-containing haeme groups.
C. Binds irreversibly with O2.
D. Increases the blood O2 carrying capacity.
E. A, B and D are all true of haemoglobin.
28. Which of the following statements best describes the reason why a kangaroo would be more likely than
a kangaroo rat to break a bone were it to slip and fall while clambering down the stairs to go skating on
the Rideau canal?
A. Skeletal mass increases disproportionately rapidly with body mass in vertebrates.
B. Because skeletal mass increases disproportionately rapidly with body mass in vertebrates, the
margin of safety against breakage remains constant.
C. Bone diameter increases disproportionately rapidly with body mass in vertebrates.
D. Even though bone diameter increases disproportionately rapidly with body mass in vertebrates, the
bones of larger vertebrates are not as strong relative to the stress that they experience as are the
bones of smaller vertebrates.
E. None of the above adequately explains why kangaroos are more prone to breaking bones than are
kangaroo rats.
29. Consider a hypothetical situation in which a burrowing lifestyle has acted as a selective pressure to
decrease body size in a desert rodent. As a result of this decrease in body size over many generations,
our hypothetical rodent will be more prone to desiccation than were its evolutionary ancestors (because
of the increase in its SA:V ratio). Which of the following best describes the cause of the change in
water relations of the desert rodent in response to the change in body size?
A. Natural selection acting on the SA:V ratio to adapt the animal to its environment.
B. An incidental change in the SA:V ratio resulting from allometry.
C. A random shift in the SA:V ratio of these desert rodents resulting from genetic drift.
D. Convergent evolution between desert rodents and desert insects.
E. Both A and D are reasonable explanations for the increased risk of desiccation in our hypothetical
desert rodent that accompanies its evolution towards a smaller body size.
30. In tuna, the counter-current arrangement of blood flow through the gill and water flow over the gill
A. Enables the retention of heat in the swimming muscles of the fish.
B. Enables the partial pressure gradient for CO2 diffusion to be maximised because blood with the
highest partial pressure of CO2 (PCO2) meets water with the lowest PCO2.
C. Enables the maintenance of a constant partial pressure gradient for gas diffusion across the entire
gas exchange surface.
D. Enables an O2 extraction efficiency of close to 100% to be achieved.
E. None of A, B, C or D is true of the counter-current blood and water flow at the tuna gill.
31. You are confronted with two worms that, on first glance, appear to be very similar. Upon closer
examination, however, you note one difference in particular that allows you to definitively identify one
specimen as an earthworm and the other as a roundworm. That key characteristic is:
A. the presence of antagonistic muscle layers immediately under the outer body covering
B. the presence of a complete digestive tract
C. the presence of a body cavity
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D. the presence of collagen in the outer body covering
E. not listed above (none of the characteristics listed above would allow an earthworm to be
distinguished from a roundworm)
32. In vertebrates, O2 and CO2 move between the gas exchange surface and the tissues primarily by:
A. Diffusion
B. Active transport
C. Convection
D. Conduction
E. None of the above describes the mechanism by which O2 and CO2 move between the gas
exchange surface and the tissues.
33. Were a phylogeny based on molecular biology (sequence homology) rather than morphological and
embryological characteristics (shared body plans) to be used, which of the following branches would be
eliminated?
A. Bilateria
B. Acoelomates
C. Protostomia
D. Eumetazoa
E. All of the above are present in both phylogenies based on sequence homology and those based on
shared body plans.
34. Which of the following characteristics distinguish animals from the other kingdoms of multicellular,
eukaryotic organisms?
A. Animals lack a way of supporting and providing shape to their bodies.
B. Animals depend on the metabolism of carbon-based chemicals for energy.
C. Animals have cells that contain distinct nuclei.
D. Animals ingest nutrients to digest them.
E. All of A, B, C and D are unique to animals and therefore distinguish them from the other kingdoms
of multicellular, eukaryotic organisms.
35. Which of the following provides a reasonable explanation of why marine mammals like whales still
come to the surface to breathe, even though this limits their ability to dive for food?
A. Marine mammals are in the process of adapting to life on land.
B. A random process like natural selection cannot possibly lead to the evolution of structures and
physiologies as complex as those required to extract oxygen directly from water.
C. The phenotypic and genotypic variation necessary to permit the evolution of a way of obtaining
oxygen directly from the water has not arisen.
D. No animal can extract oxygen directly from the water.
E. All of A, B, C and D provide reasonable explanations of why marine mammals must surface to
breathe.
36. Both camels and voles may use huddling as a strategy in the regulation of their body temperature. The
advantage of huddling to both of these organisms is that:
A. It reduces the effective SA:V ratio, minimising heat exchange with the environment.
B. It increases the effective SA:V ratio, thereby aiding in the retention of body heat.
C. It decreases radiant and conductive heat loss to the environment.
D. It decreases radiant and conductive heat gain from the environment.
E. Both A and C describe the value of huddling as a thermoregulatory strategy to camels and voles.
37. Animals that feed on animals that they have killed are called:
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A.
B.
C.
D.
E.
Detritovores
Herbivores
Predators
Parasites
Both A and C.
38. Which of the following factors enables plethodontid salamanders to survive and flourish without a
specialised respiratory surface?
A. Their small size.
B. The fact that they are ectothermic.
C. The humid habitat in which they live.
D. The relatively high solubility of O2 in air.
E. All of A, B, C and D contribute to the ability of plethodontid salamanders to carry out gas exchange
without lungs or gills.
39. Inorganic skeletal materials (like CaPO4) have some disadvantages relative to organic skeletal
materials (like chitin), including the fact that:
A. Mineral materials are less rigid than organic materials.
B. Mineral materials are more prone to failing catastrophically than organic materials.
C. Mineral materials are denser than organic materials.
D. Mineral materials are less brittle than organic materials.
E. Both B and C are true of mineral materials in comparison to organic skeletal materials.
40. The colour of the haemoglobin in the left ventricle of the mammalian heart can best be described as:
A. Bright red
B. Green
C. Blue-red
D. Blue
E. None of A, B, C or D describes the colour of the haemoglobin in the mammalian left ventricle.
41. In which of the following species would you expect the male and female gametes to be most similar in
size?
A. The basket sponge, a sedentary marine member of Phylum Porifera.
B. The scorpionfly Panorpa, a terrestrial insect employing internal fertilisation; males gain mates by
presenting the female with a gift of food which she consumes while he mates with her.
C. The three-spined stickleback, Gasterosteus aculeatus, a freshwater fish species in which the male
bears prime responsibility for the care of the eggs and young.
D. The dunnock, Prunella modularis, a small nondescript British bird that has been the focus of
intense research effort because of the complexities of its mating system.
E. Without more information, no reasonable guesses can be made about the relative size of the eggs
and sperm in these species.
42. The Cl- concentration of seawater is approximately 552 mmol L-1. Which of the following marine
vertebrates can drink seawater without becoming dehydrated?
A. Flounder – urine Cl- concentration  160 mmol L-1
B. Seagull – urine Cl- concentration  257 mmol L-1
C. Galapagos marine iguana – urine Cl- concentration  110 mmol L-1
D. Whale – urine Cl- concentration  820 mmol L-1
E. All of A, B, C, and D can drink seawater without becoming dehydrated.
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43. Which of the following would be more likely to be found in a nocturnal vertebrate than in a vertebrate
that is active primarily during the day?
A. A tapetum (a reflecting layer behind the retina).
B. An iris.
C. Rods and cones.
D. A fovea.
E. All of A, B, C and D are found in all vertebrates.
Very short answer type questions
44. Fill in the table below (¼ mark each):
Deuterostome
Protostome
Type of egg cleavage
Radial
Spiral
Placement of nerve cord
Dorsal
Ventral
Type of coelom formation
Enterocoelous
Schizocoelous
45. The rate of O2 uptake by a fish would be negatively impacted by an increase/decrease (choose one) in
the thickness of the gill epithelium in conjunction with an increase/decrease (choose one) in the partial
pressure of O2 in the blood of the fish (½ mark each).
46. Swimming and flying animals both undertake locomotion in a fluid environment and therefore face
similar problems. There are, however, important quantitative differences between swimmers and flyers
in terms of the forces faced. For example, the __________drag______________________ on
swimmers is greater than that on flyers because of the higher density and viscosity of water relative to
air. However, because water is denser than air, swimmers can make use of
_________________neutral buoyancy_____________ to combat the force of gravity (½ mark each).
10
100
Hb-O2 (% sat.)
47. In mammals, the developing embryo obtains O2 from its
mother’s blood via the placenta. The figure at right shows the
O2 equilibrium curve for the maternal haemoglobin. On the
same axes, sketch the O2 equilibrium curve for the foetal
haemoglobin.
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P50
0
0
PO2 (torr)
100
48. List two examples of structural adaptations that may be present in the gastrointestinal tract to facilitate
its function (½ mark each):
(a) __villi and microvilli to increase surface area_______________
(b) __rumen (specialised stomach for hosting microorganisms that carry out cellulose and lignin digestion)
49. What physiological mechanism do fish gills and fox legs have in common?
______________counter current exchangers________________________________________________
50. The evolutionary lineage of a species is termed its ___phylogeny__________________, whereas its
development from egg to adult organism is termed its ____ontogeny_________________. (2 marks)
51. At what point in the mammalian circulatory system is the total cross-sectional area of blood vessels the
highest? __capillaries___________________________. At this point in the circulatory system, blood is
flowing at its greatest/lowest (pick one) velocity. (2 marks)
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52. Complete the following table: (4 marks)
Animal
Type of circulatory system
Heart type
Human
Closed
Chamber
Bumblebee
Open
Peristaltic
Squid
closed
chamber
nematode
Open
Simple, collapsible tube operated by
action of surrounding muscles
Earthworm
Clam
Closed
peristaltic
open
chamber
Short answer type questions
53. In formulating his theory of evolution by natural selection, one of the observations that greatly troubled
Charles Darwin was the presence in some animals of traits that were clearly detrimental to survival, an
example of such a trait being the extraordinarily long tail of the male peacock. Does the presence of
such traits contradict the theory of evolution by natural selection? Why or why not? Explain how such
traits might arise in a population.
The presence of such traits does not contradict the theory of evolution by natural selection because natural
selection operates to maximise reproductive success, and these traits enhance reproductive success (albeit
at the probable cost of increased predation). These traits enhance reproductive success because they are
attractive to females. If a male trait is attractive to females and is used by females as a means of choosing
a mate, the males possessing this trait will experience increased reproductive success. Assuming that the
trait has a genetic basis, the attractive trait will be passed on to their offspring, with male offspring, in turn,
being more attractive to females and experiencing enhanced reproductive success. Through this “runaway
sexual selection”, extreme traits that are detrimental to survival may become fixed in the population.
54. Compare and contrast the basic structure of nervous and endocrine systems, and explain how a
neurosecretory cell combines the properties of both.
In the endocrine system, an endocrine cell releases a chemical messenger termed a hormone into the
circulatory system, which carries it to its target tissue. In the nervous system, messages are transmitted as
electrical signals along nerve cells (or neurons). The message is passed from one neuron to the next by
means of a chemical messenger termed a neurotransmitter. Thus, while both systems make use of
chemical messengers, they are the sole signal in the endocrine system. Moreover, only the endocrine
system makes use of the circulatory system to transmit its signal. A neurosecretory cells is a neuron that
releases its neurotransmitter, in this case termed a neurohormone, into the circulation to be carried to the
target tissue. Thus, it combines the nerve cell of the nervous system with the transmission of a chemical
message via the circulatory system of the endocrine system.