Campbell Biology: Concepts and Connections, 8e (Reece et al.)
Chapter 25 Control of Body Temperature and Water Balance
25.1 Multiple-Choice Questions
1) Thermoregulation, an important part of homeostasis, is defined as
A) a mechanism for utilizing body fat for energy.
B) reduced blood flow to an animal’s extremities in order to conserve heat.
C) the maintenance of internal body temperature within an optimal range despite change in
external temperature.
D) the mechanisms that allow an animal to hibernate without food or drink.
2) Animals that maintain internal body temperature using heat generated by their own
metabolism are called
A) endotherms.
B) ectotherms.
C) reptiles.
D) amphibians.
3) It is a cool winter evening, and you are feeling a little chilled. To warm yourself up, you sip
some hot tea. As you swallow, you can feel the tea warm your mouth and throat. The drink is
warming you up by the process of
A) convection.
B) induction.
C) conduction.
D) radiation.
4) Which of the following processes involves heat exchange between an animal and its
environment?
A) irradiation
B) convection
C) induction
D) evaporation
5) Which of the following physiological responses occurs in the human body when it becomes
overheated?
A) slowing of the heart rate
B) constriction of blood vessels in the skin
C) increased blood flow to the skin
D) retention of water
6) The transfer of heat from arteries carrying warm blood past veins returning cooler blood is an
example of
A) insulation.
B) countercurrent heat exchange.
C) evaporative cooling.
D) behavioral thermoregulation.
7) To enhance heat loss, humans sweat; this is an adaptation known as
A) insulation.
B) evaporative cooling.
C) irradiation.
D) conduction.
8) Marine animals that have body fluids with a solute concentration equal to that of the
surrounding seawater are
A) osmoregulators.
B) osmoconformers.
C) hypotonic.
D) hypertonic.
9) Which of the following statements regarding freshwater fish is true?
A) Freshwater fish frequently drink to obtain salt ions.
B) Freshwater fish use their gills to actively take up salt ions.
C) Freshwater fish lose water through their gills by osmosis.
D) Freshwater fish do not produce urine.
10) To conserve precious salts, freshwater fish
A) produce small amounts of urine and exert as little energy as possible.
B) drink almost no water and produce large amounts of dilute urine.
C) excrete salt ions and small amounts urine
D) eliminate water by osmosis and swim in short, small bursts of energy.
11) Which of the following statements regarding saltwater fish is true?
A) The concentration of solutes in the internal fluids of saltwater fish is much lower than that in
the surrounding water.
B) The concentration of solutes in the internal fluids of saltwater fish is higher than that in the
surrounding environment.
C) Saltwater fish produce large amounts of diluted urine.
D) Saltwater fish must visit freshwater streams and rivers entering the ocean to maintain the
correct concentration of solutes in their internal fluids.
12) Which of the following by-products of metabolism is the most toxic?
A) carbon monoxide
B) ammonia
C) urea
D) lactic acid
13) Which of the following kinds of animals excrete their nitrogenous waste entirely as
ammonia?
A) birds
B) fish
C) garden snails
D) insects
14) What is the advantage of excreting nitrogenous waste in the form of ammonia?
A) Ammonia is less toxic than uric acid.
B) Ammonia is less soluble than uric acid.
C) Ammonia excretion conserves energy.
D) Ammonia does not diffuse across cell membranes.
15) The mechanism for excreting nitrogenous waste in aquatic animals was ineffective on land
because
A) land animals concurrently developed a more efficient reproduction system.
B) land animals found better food sources.
C) land animals had a more difficult time with water balance than aquatic species since water
was not always available on land.
D) aquatic animals did not have as much protein in their diets as did land animals.
16) Natural selection is nature’s mechanism for selecting characteristics that best adapt the
animal to its environment. Mammals have evolved a sophisticated mechanism for eliminating
nitrogenous wastes that involves
A) secretion through cell membranes.
B) forming urea and storing it in concentrated solution.
C) producing uric acid and excreting it with feces.
D) recycling urea and using it as an energy source.
17) Birds, like other animals, must eliminate ammonia or urea. They do so by converting it to
A) amino acids.
B) ammonium ions.
C) sodium chloride.
D) uric acid.
18) Which of the following statements about uric acid is true?
A) Animals that excrete uric acid avoid the problem of water loss associated with excretion of
urea.
B) Uric acid is more soluble in water than urea.
C) The darker material in bird droppings is mostly uric acid.
D) Uric acid cannot be excreted because of its toxicity.
19) Which of the following is a function of the vertebrate liver?
A) combining ammonia and carbon dioxide to form urea
B) synthesizing ammonia from uric acid
C) excreting urea
D) producing urea from uric acid and carbon dioxide
20) Which of the following is a function of the human urinary system?
A) detoxification
B) elimination of undigested foods
C) maintenance of water balance
D) production of ammonia
21) What is the functional unit of the kidney?
A) renal unit
B) Bowman’s capsule
C) nephron
D) glomerulus
22) Through which of the following structures does urine leave the bladder?
A) ureter
B) urethra
C) renal medulla
D) distal convoluted tubule
23) Which of the following statements regarding the urinary system is true?
A) Bowman’s capsule envelops the glomerulus.
B) Most glomeruli are located in the renal medulla.
C) The urinary bladder receives ammonia for excretion.
D) The urethra is responsible for transporting urea from the kidney to the urinary bladder.
24) Which of the following options correctly lists the structures in the kidney in the order in
which fluid flows through them?
A) proximal tubule, Bowman’s capsule, loop of Henle, distal tubule, glomerulus
B) Bowman’s capsule, proximal tubule, loop of Henle, distal tubule, glomerulus
C) glomerulus, Bowman’s capsule, proximal tubule, loop of Henle, distal tubule
D) glomerulus, proximal tubule, distal tubule, Bowman’s capsule, loop of Henle
25) During filtration in the glomerulus, which of the following enters Bowman’s capsule from
the bloodstream?
A) ammonia and red blood cells
B) nucleic acids
C) lymphocytes
D) water
26) The first step in the formation of urine is the
A) secretion of hydrogen ions into the kidney tubules.
B) formation of filtrate that enters Bowman’s capsule.
C) secretion of urea into the renal pelvis.
D) reabsorption of nutrients by Bowman’s capsule.
27) Urine flows from the collecting duct into the
A) ureter.
B) urethra.
C) renal pelvis.
D) distal tubule.
28) The overall process that refines the filtrate and ultimately returns water and valuable solutes
to the blood is known as
A) reabsorption.
B) excretion.
C) collection.
D) purification.
29) Secretion is the movement of substances such as drugs or toxic molecules from the
________ into the ________.
A) nephron tubule; glomerulus
B) glomerulus; nephron tubule
C) blood; filtrate
D) urinary bladder; outside
30) During production of urine, a major function of the kidney is
A) water conservation.
B) amino acid production.
C) detoxification.
D) uric acid production.
31) Water moves out of filtrate in the nephron tubule into the interstitial fluid by
A) capillary action.
B) refinement.
C) secretion.
D) osmosis.
32) Where along the nephron is glucose reabsorbed from the filtrate back into the blood?
A) distal tubule
B) loop of Henle
C) proximal tubule
D) Bowman’s capsule
33) Why must water that has moved to the interstitial fluid in the medulla be quickly removed
from the interstitial fluid?
A) to prevent dilution of urine
B) to prevent destruction of the concentration gradient necessary for water reabsorption
C) to equilibrate the concentration of solutes in the cortex and medulla
D) to maintain an environment for transport of nutrients
34) What is the function of urea reabsorption in the collecting ducts of the kidney?
A) It restores the correct concentration of blood urea.
B) It increases the osmotic concentration of the interstitial fluid in the renal medulla so that more
water can be extracted from the urine.
C) It reduces the salinity of the renal medulla and thus helps regulate how much water is
reabsorbed from the urine.
D) It moves the urea into the ascending limb of the loop of Henle so that it can be excreted from
there in the urine.
35) What is the function of antidiuretic hormone?
A) to increase urination
B) to increase water reabsorption
C) to stimulate sodium reabsorption
D) to counter the effects of alcohol consumption
36) The dialyzing solution used during kidney dialysis functions much like a fluid associated
with a nephron. What is the fluid?
A) interstitial fluid
B) the filtrate in the proximal tubule
C) the filtrate in the loop of Henle
D) the filtrate in the distal tubule
37) In a dialysis machine, wastes are removed from blood plasma by the process of
A) filtration.
B) diffusion.
C) reabsorption.
D) absorption.
38) When a dolphin consumes a large volume of water and electrolytes, it must be able to get rid
of large volumes of water via urine and feces. This is an example of the process of
A) osmoregulation.
B) convection.
C) thermoregulation.
D) countercurrent heat exchange.
39) A salamander is a vertebrate that spends part of its life cycle in water (juvenile stage) and
part on land (adult stage). In both life stages, the salamander’s body temperature depends on its
surrounding environment, so the salamander demonstrates _________ behavior.
A) endothermic
B) ectothermic
C) huddling
D) regulatory
40) If a person sits on a cool floor, heat from that person is transferred to the floor. This is an
example of
A) convection.
B) radiation.
C) conduction.
D) evaporation.
41) Plants have specific temperatures (or temperature ranges) that allow for maximum growth. A
process by which heat from ________ is transferred from the sun to leaves helps give plants
these ideal temperatures.
A) convection
B) evaporation
C) conduction
D) radiation
42) When humans are cold, they often shiver. Shivering increases their ________, thereby
warming their bodies.
A) metabolic heat production
B) insulation
C) circulatory adaptation
D) evaporative cooling
43) A woman running a marathon collapses at the finish line and is rushed to the hospital. The
physicians determine that she has lost a large amount of water and salts from excessive sweating.
Which of the following would be an appropriate course of action?
A) Determine the woman’s intracellular fluid levels so that they can provide a fluid replacement
therapy that will regain isotonic conditions of salt and water.
B) Determine the woman’s intracellular fluid levels so that they can provide a fluid replacement
therapy that will regain hypertonic conditions of salt and water.
C) Determine the woman’s intracellular fluid levels so that they can provide a fluid replacement
therapy that will regain hypotonic conditions of salt and water.
D) Determine the woman’s intracellular fluid levels so that they can provide a fluid replacement
therapy that will provide a measure of metabolic heat production.
44) The text describes how emperor penguins use a huddling behavior to conduct heat
efficiently. Similarly, honeybees conduct heat within their hives by huddling together and then
changing positions from the center of the huddle to the edges in order to keep heat circulating.
When it is warm, however, the bees transport water into their hives and then beat their wings in
order to make ________ cooling possible.
A) conductive and convective
B) isotonic and convective
C) evaporative and convective
D) evaporative and conductive
45) Cormorants are sea-dwelling birds that consume high levels of salt from the seawater they
drink. To get rid of this excess salt, cormorants “sneeze” out the salt that has collected in a
localized area near their sinuses. This process is an example of
A) osmoregulation.
B) thermoregulation.
C) conduction.
D) radiation.
46) The common waste product in bears (mammals) is ________, while most saltwater fish get
rid of wastes through ________.
A) ammonia; urea
B) uric acid; urea
C) urea; ammonia
D) ammonia; uric acid
47) Which of the following options correctly lists the order of the four main processes that occur
in the urinary system?
A) filtration, excretion, reabsorption, secretion
B) excretion, filtration, reabsorption, secretion
C) filtration, reabsorption and secretion occurring simultaneously, excretion
D) reabsorption and secretion occurring simultaneously, excretion, filtration
48) If valuable solutes were not adequately reabsorbed from filtrate, what would occur?
A) The excretion process could not be completed.
B) The solutes would be excreted.
C) The filtration process could not be completed.
D) The solutes would be reabsorbed.
49) A logical treatment plan for patients with high ADH levels would include
A) less fluids.
B) more fluids.
C) less potassium.
D) more potassium.
50) Like humans, cats can experience kidney failure. Unlike humans, however, cat kidney
dialysis as a treatment option is not widely available and used. Rather, efforts are made to treat
any complications that arise from failing kidneys such as low potassium or high phosphate
levels. When low potassium levels are identified, potassium supplements are given to return cells
to a balanced potassium-water level. This is an example of an effort to maintain
A) osmoregulation.
B) thermoregulation.
C) convection.
D) evaporation.
51) The main function of antidiuretic hormone (ADH) is to help achieve homeostasis of water
balance. All of the following are reasons to test for abnormal ADH levels except
A) swelling due to fluid buildup.
B) excessive urination.
C) feeling thirsty after exercising.
D) overhydration.
52) Urine differs in composition from the fluid that first enters a nephron tubule by filtration
because
A) the filtrate contains less water.
B) the filtrate contains red blood cells.
C) the filtrate has more salts.
D) the filtrate does not contain urea.
25.2 Art Questions
1) Which arrow in this figure shows heat transfer by conduction?
A) arrow A
B) arrow B
C) arrow C
D) arrow D
2) Which part of the nephron shown is its proximal tubule?
A) part A
B) part B
C) part C
D) part D
3) Which arrow in this schematic view of the nephron shows reabsorption?
A) arrow A
B) arrow B
C) arrow C
D) arrow D
The following questions relate to the three figures above, which indicate how the tubules in the
kidney respond to the administration of the hormone vasopressin.
4) The hypothesis that scientists who collected these data were most likely testing is that
A) the permeability of collecting changes over time.
B) collecting tubules have aquaporins.
C) permeability change is linked to the number of aquaporins.
D) aquaporins allow water into kidney tubules.
5) The density of the aquaporins in the presence of vasopressin was approximately
A) half as much as before the administration of vasopressin.
B) twice as much as before the administration of vasopressin.
C) four times as much as before the administration of vasopressin.
D) unchanged by the administration of vasopressin.
25.3 Scenario Questions
After reading the paragraph below, answer the questions that follow.
Most fishes can live either in freshwater or in saltwater habitats, but not in both. If you move a
marine fish from the ocean to a lake, it will quickly die, and vice versa. However, a small
number of fish species are capable of moving between the two environments. Salmon are
osmoregulators that hatch in rivers, spend most of their lives in the ocean, and return to the river
where they were born in order to breed.
1) When a salmon moves from the ocean to a freshwater environment, you would expect its
urine volume to ________ and its rate of salt absorption to ________.
A) increase; remain the same
B) increase; increase
C) decrease; decrease
D) decrease; increase
2) When a salmon leaves the river and moves out to sea, you would expect ________ to leave its
body by osmosis and that excess ________ would need to be pumped out.
A) salt; water
B) water; salt
C) salt; salt
D) water; water
19
After reading the paragraph below, answer the questions that follow.
In 2011, scientists investigated whether the salts that are spread on icy roads to melt the ice are
diluted enough by spring rainfall so that they do not have negative effects on amphibian species
that breed in nearby areas. They exposed clutches (groups of eggs) of salamanders to three test
conditions with varying salt concentrations (road salts mixed with dechlorinated tap water) to
simulate salt concentrations of small pools of water located near highways that are typically fed
by rain—areas where salamanders often lay their eggs. After 9 days, the scientists placed the
three groups in “normal” water and measured how much body mass the salamanders lost every 3
days for 9 days. They chose to measure change in mass because salamanders are able to take in
water, which helps lower the chances of salamander embryos dying from freezing, disease, or
predation. The table below provides partial results of this study.
Group
Chloride
concentration in
test conditions
Total % mass lost
after 9 days of
exposure to test
conditions
Total % mass
regained after 9
days in normal
water conditions
Additional %
mass lost after 9
days in normal
water conditions
1
145 mg/L
20%
15%
0%
2
945 mg/L
35%
0%
10%
3) This study is considering the salamander clutches’ ability to maintain the process of
A) osmoregulation.
B) thermoregulation.
C) concurrent heat exchange.
D) diffusion.
4) What conclusion did scientists likely draw from this study?
A) Rainy conditions may not be enough to dilute road salts that have high salt concentrations.
Therefore, salamander clutches will experience minimal physiological damage.
B) Rainy conditions are enough to completely dilute road salts that have high salt concentrations.
Therefore, salamander clutches will not experience any permanent physiological damage.
C) Rainy conditions are enough to completely dilute road salts that have high salt concentrations.
Therefore, salamander clutches will experience minimal physiological damage.
D) Rainy conditions may not be enough to dilute road salts that have high salt concentrations.
Therefore, salamander clutches will face irreversible physiological damage.
5) There was a third group (group 3) in this study that experienced the same test conditions as
groups 1 and 2 except that the water to which group 3 was exposed always had a chloride
concentration (mg/L) that salamander clutches would normally experience (that is, with no road
salts in the water). How would you describe this group?
A) an experimental group
B) a control group
C) a dependent variable
D) an independent variable
6) What do you predict that group 3 demonstrated?
A) higher mass lost from its initial conditions than group 2
B) the same mass lost from its initial conditions as group 1
C) no mass lost from its initial conditions
D) the highest mass loss of all groups