front 5 5) The fluid with the highest osmolarity is
A) distilled water.
B) plasma in birds.
C) plasma in mammals.
D)
seawater in a tidal pool.
E) estuarine water. | |
front 6 6) Birds that live in marine environments and thus lack access to
fresh drinking water
A) osmoregulate without using a transport
epithelium for this purpose.
B) drink seawater and secrete
excess ions through their kidneys only.
C) drink seawater and
secrete excess ions mainly through their nasal salt glands.
D)
have plasma that is isoosmotic to ocean water.
E) obtain water
by eating only osmoregulating prey. | |
front 7 7) Osmoconforming sharks take in water, as needed,
A) by
migrating to freshwater rivers to drink fresh water.
B) via
osmosis, as their body cells are slightly hyperosmotic to seawater.
C) via active transport of water across the cells on their
gills.
D) by water diffusion from seawater, which is
hyperosmotic to the fluids in their cells.
E) by selective
transport of water molecules across the wall of the gut. | |
front 8 8) A human who has no access to fresh water but is forced to drink
seawater instead
A) will thrive under such conditions, as long
as he has lived at the ocean most of his life.
B) will excrete
more water molecules than taken in, because of the high load of ion
ingestion.
C) will develop structural changes in the kidneys to
accommodate the salt overload.
D) will find that drinking
saltwater satiates his thirst.
E) will risk becoming
overhydrated within 12 hours. | |
front 9 9) Many marine and freshwater bony fish achieve osmoregulation via
A) loss of water through the gills.
B) gain of salt
through the gills.
C) loss of water in the urine.
D) no
drinking of water.
E) gain of water through food. | |
front 10 10) Unlike most bony fishes, sharks maintain body fluids that are
isoosmotic to seawater, so they are considered by many to be
osmoconformers. Nonetheless, these sharks osmoregulate at least
partially by
A) using their gills and kidneys to rid themselves
of sea salts.
B) monitoring dehydration at the cellular level
with special gated aquaporins.
C) tolerating high urea
concentrations that balance internal salt concentrations to seawater
osmolarity.
D) synthesizing trimethylamine oxide, a chemical
that binds and precipitates salts inside cells.
E) possessing a
special adaptation that allows their cells to operate at an
extraordinarily high salt concentration. | |
front 11 11) The necropsy (postmortem analysis) of a freshwater fish that died
after being placed accidentally in saltwater would likely show that
A) loss of water by osmosis from cells in vital organs resulted
in cell death and organ failure.
B) high amounts of salt had
diffused into the fish's cells, causing them to swell and lyse.
C) the kidneys were not able to keep up with the water removal
necessary in this hyperosmotic environment, creating an irrevocable
loss of homeostasis.
D) the gills became encrusted with salt,
resulting in inadequate gas exchange and a resulting asphyxiation.
E) brain cells lysed as a result of increased osmotic pressure
in this hyperosmotic environment, leading to death by loss of
autonomic function. | |
front 12 12) Urea is produced in the
A) liver from NH₃ and CO₂.
B)
liver from glycogen.
C) kidneys from glucose.
D) kidneys
from glycerol and fatty acids.
E) bladder from uric acid and H₂O. | |
front 13 13) Urea is
A) insoluble in water.
B) more toxic to human
cells than ammonia.
C) the primary nitrogenous waste product of
humans.
D) the primary nitrogenous waste product of most birds.
E) the primary nitrogenous waste product of most aquatic invertebrates. | |
front 14 14) Which nitrogenous waste has the greatest number of nitrogen
atoms?
A) ammonia
B) ammonium ions
C) urea
D)
uric acid | |
front 15 15) Ammonia is likely to be the primary nitrogenous waste in living
conditions that include
A) lots of fresh water flowing across
the gills of a fish.
B) lots of seawater, such as a bird living
in a marine environment.
C) lots of seawater, such as a marine
mammal (e.g., a polar bear).
D) a terrestrial environment, such
as that supporting crickets.
E) a moist system of burrows, such
as those of naked mole rats. | |
front 16 16) Among vertebrate animals, urea
A) is made in the kidneys
and immediately excreted.
B) is added to the air in the lungs to
be exhaled, along with carbon dioxide.
C) is made in the liver
by combining two ammonia molecules with one carbon dioxide.
D)
is made in the pancreas and added to the intestinal contents, along
with bile salts, for excretion.
E) is rarely the nitrogenous
waste of choice. | |
front 17 17) The nitrogenous waste that requires the most energy to produce is
A) ammonia.
B) ammonium.
C) urea.
D) uric acid. | |
front 18 18) Excessive formation of uric acid crystals in humans leads to
A) a condition called diabetes, where excessive urine formation
occurs.
B) a condition of insatiable thirst and excessive urine
formation.
C) gout, a painful inflammatory disease that
primarily affects the joints.
D) the absence of urea in the
urine.
E) osteoarthritis, an inevitable consequence of aging. | |
front 19 19) Ammonia
A) is soluble in water.
B) can be stored in
the body as a precipitate.
C) has low toxicity relative to urea.
D) is metabolically more expensive to synthesize than urea.
E) is the major nitrogenous waste excreted by insects. | |
front 20 20) The advantage of excreting nitrogenous wastes as urea rather than
as ammonia is that
A) urea can be exchanged for Na+.
B)
urea is less toxic than ammonia.
C) urea requires more water for
excretion than ammonia.
D) urea does not affect the osmolar
gradient.
E) less nitrogen is removed from the body. | |
front 21 21) The primary nitrogenous waste excreted by birds is
A)
ammonia.
B) nitrate.
C) nitrite.
D) urea.
E)
uric acid. | |
front 22 22) Which nitrogenous waste requires hardly any water for its
excretion?
A) amino acids
B) urea
C) uric acid
D) ammonia
E) nitrogen gas | |
front 23 23) In animals, nitrogenous wastes are produced mostly from the
catabolism of
A) starch and cellulose.
B) triglycerides
and steroids.
C) proteins and nucleic acids.
D)
phospholipids and glycolipids.
E) fatty acids and glycerol. | |
front 24 24) Birds secrete uric acid as their nitrogenous waste because uric
acid
A) is readily soluble in water.
B) is metabolically
less expensive to synthesize than other excretory products.
C)
requires little water for nitrogenous waste disposal, thus reducing
body mass.
D) excretion allows birds to live in desert environments. | |
front 25 25) Among the following choices, the most concentrated urine is
excreted by
A) frogs.
B) kangaroo rats.
C) humans.
D) desert tortoises.
E) birds. | |
front 26 26) Materials are returned to the blood from the filtrate by which of
the following processes?
A) filtration
B) ultrafiltration
C) selective reabsorption
D) secretion
E) active transport | |
front 27 27) Excretory structures known as protonephridia are present in
A) flatworms.
B) earthworms.
C) insects.
D)
vertebrates.
E) cnidarians. | |
front 28 28) Excretory organs known as Malpighian tubules are present in
A) earthworms.
B) flatworms.
C) insects.
D)
jellyfish.
E) sea stars. | |
front 29 29) The osmoregulatory/excretory system of a freshwater flatworm is
based on the operation of
A) protonephridia.
B)
metanephridia.
C) Malpighian tubules.
D) nephrons.
E) ananephredia. | |
front 30 30) Freshwater flatworms form a urine that is typically
A) of
high solute concentration, in order to conserve body fluids.
B)
of very low volume, in order to conserve body fluids.
C) of high
solute concentration and very low volume, in order to conserve body
fluids.
D) of high solute concentration and of high volume,
matching their normal fluid uptake.
E) of low solute
concentration and of high volume, matching their normal fluid uptake. | |
front 31 31) The osmoregulatory process called secretion refers to the
A) formation of filtrate at an excretory structure.
B)
reabsorption of nutrients from a filtrate.
C) selective
elimination of excess ions and toxins from body fluids.
D)
formation of an osmotic gradient along an excretory structure.
E) expulsion of urine from the body. | |
front 32 32) The osmoregulatory/excretory system of an earthworm is based on
the operation of
A) protonephridia.
B) metanephridia.
C) Malpighian tubules.
D) nephrons.
E) ananephredia. | |
front 33 33) The osmoregulatory/excretory system of an insect is based on the
operation of
A) protonephridia.
B) metanephridia.
C)
Malpighian tubules.
D) nephrons.
E) ananephredia. | |
front 34 34) Which of the following pairs of organisms excrete nitrogenous
wastes in the form of uric acid?
A) mice and birds
B)
insects and birds
C) lions and horses
D) humans and frogs
E) fish and turtles | |
front 35 35) Choose a pair that correctly associates the mechanism for
osmoregulation or nitrogen removal with the appropriate animal.
A) metanephridiumflatworm
B) Malpighian tubulefrog
C) kidneyinsect
D) flame bulbsnake
E) direct
cellular exchangemarine invertebrate | |
front 36 36) An excretory system that is partly based on the filtration of
fluid under high hydrostatic pressure is the
A) flame bulb
system of flatworms.
B) protonephridia of rotifers.
C)
metanephridia of earthworms.
D) Malpighian tubules of insects.
E) kidneys of vertebrates. | |
front 37 37) The transfer of fluid from the glomerulus to Bowman's capsule
A) results from active transport.
B) transfers large
molecules as easily as small ones.
C) is very selective as to
which subprotein-sized molecules are transferred.
D) is mainly a
consequence of blood pressure in the capillaries of the glomerulus.
E) usually includes the transfer of red blood cells into
Bowman's capsule. | |
front 38 38) Within a normally functioning kidney, blood can be found in
A) the vasa recta.
B) Bowman's capsule.
C) the loop
of Henle.
D) the proximal tubule.
E) the collecting duct. | |
front 39 39) A person with alkalosis will likely excrete urine that has
abnormally high levels of
A) bicarbonate ions.
B) sodium
ions.
C) glucose.
D) ammonia.
E) NaOH. | |
front 40 40) The filtrate in the renal pelvis enters directly from
A)
the loop of Henle.
B) the collecting duct.
C) Bowman's
capsule.
D) the proximal tubule.
E) the glomerulus. | |
front 41 41) Juxtamedullary nephrons can concentrate salt effectively in the
renal medulla because of their long
A) loops of Henle.
B)
distal convoluted tubules.
C) Bowman's capsules.
D)
proximal convoluted tubules.
E) glomeruli. | |
front 42 42) The filtrate in the proximal convoluted tubule of the human does
not normally include
A) ions.
B) glucose.
C) plasma
proteins.
D) amino acids.
E) dissolved gasses. | |
front 43 43) Human urine is usually more acidic than most other body fluids
because
A) hydrogen ions are actively moved into the filtrate.
B) the sodium transporter exchanges one hydrogen ion for each
sodium ion.
C) excreted plasma proteins are nearly all acidic
ions.
D) excreted amino acids are in abundance.
E)
potassium and sodium exchange generates lots of acidity. | |
front 44 44) The osmolarity of human urine
A) can be four times as great
as normal osmolarity of human plasma.
B) is always exactly equal
to plasma osmolarity.
C) is always less than plasma osmolarity.
D) is always greater than plasma osmolarity.
E) is
determined primarily by the concentration of glucose. | |
front 45 45) A primary reason that the kidneys have one of the highest
metabolic rates of all body organs is that
A) it stores the
body's excess fats.
B) it has membranes of varying permeability
to water.
C) it operates an extensive set of active-transport
ion pumps.
D) it is the body's only means of shedding excess
nutrients.
E) it has an abundance of myogenic smooth muscle. | |
front 46 46) Low selectivity of solute movement is a characteristic of
A) salt pumping to control osmolarity.
B) H+ pumping to
control pH.
C) reabsorption mechanisms along the proximal
tubule.
D) filtration from the glomerular capillaries.
E)
secretion along the distal tubule. | |
front 47 47) If ATP production in a human kidney was suddenly halted, urine
production would
A) come to a complete halt.
B) decrease,
and the urine would be hypoosmotic compared to plasma.
C)
increase, and the urine would be isoosmotic compared to plasma.
D) increase, and the urine would be hyperosmotic compared to
plasma.
E) decrease, and the urine would be isoosmotic compared
to plasma. | |
front 48 48) Compared to wetland mammals, water conservation in mammals of
arid regions is enhanced by having more
A) juxtamedullary
nephrons.
B) Bowman's capsules.
C) ureters.
D)
podocytes.
E) urinary bladders. | |
front 49 49) Processing of filtrate in the proximal and distal tubules
A) achieves the sorting of plasma proteins according to size.
B) achieves the conversion of toxic ammonia to less toxic urea.
C) maintains homeostasis of pH in body fluids.
D)
regulates the speed of blood flow through the nephrons.
E)
reabsorbs urea to maintain osmotic balance. | |
front 50 50) In humans, the transport epithelial cells in the ascending loop
of Henle
A) are the largest epithelial cells in the body.
B) are not in contact with interstitial fluid.
C) have
plasma membranes of low permeability to water.
D) have 50% of
their cell mass made of smooth endoplasmic reticulum.
E) are not
affected by high levels of nitrogenous wastes. | |
front 51 51) The typical osmolarity of human blood is
A) 30 mosm/L.
B) 100 mosm/L.
C) 200 mosm/L.
D) 300 mosm/L.
E) 500 mosm/L. | |
front 52 52) Trauma to the human kidney could result in a urinary filtrate
containing an abnormally high level of
A) fatty acids.
B)
glucose.
C) salts.
D) erythrocytes.
E) vitamins. | |
front 53 53) When stimulated by aldosterone, the reabsorption of Na+ is
increased along
A) the loop of Henle.
B) the collecting
duct.
C) Bowman's capsule.
D) the proximal tubule.
E) the distal tubule. | |
front 54 54) Increased ADH secretion is likely after
A) drinking lots of
pure water.
B) sweating-induced dehydration increases plasma
osmolarity.
C) ingestion of ethanol (drinking alcoholic drinks).
D) eating a small sugary snack.
E) blood pressure is
abnormally high. | |
front 55 55) After blood flow is artificially reduced at one kidney, you would
expect that kidney to secrete more of the hormone known as
A)
erythropoietin.
B) angiotensinogen.
C) renin.
D)
antidiuretic hormone.
E) atrial natriuretic peptide. | |
front 56 56) After drinking alcoholic beverages, increased urine excretion is
the result of
A) increased aldosterone production.
B)
increased blood pressure.
C) inhibited secretion of antidiuretic
hormone (ADH).
D) increased reabsorption of water in the
proximal tubule.
E) the osmoregulator cells of the brain
increasing their activity. | |
front 57 57) Osmoregulatory adjustment via the renin-angiotensin-aldosterone
system can be triggered by
A) sleeping for one hour.
B)
severe sweating on a hot day.
C) eating a bag of potato chips.
D) eating a pizza with olives and pepperoni.
E) drinking
several glasses of water. | |
front 58 58) Antidiuretic hormone (ADH) functions at the cellular level by
A) stimulating the reabsorption of glucose through channel
proteins.
B) triggering the synthesis of an enzyme that makes
the phospholipid bilayer more permeable to water.
C) causing
membranes to include more phospholipids that have unsaturated fatty
acids.
D) causing an increase in the number of aquaporin
molecules of collecting duct cells.
E) decreasing the speed at
which filtrate flows through the nephron, leading to increased
reabsorption of water. | |
front 59 59) ADH and RAAS work together in maintaining osmoregulatory
homeostasis through which of the following ways?
A) ADH
regulates the osmolarity of the blood and RAAS regulates the volume of
the blood.
B) ADH regulates the osmolarity of the blood by
altering renal reabsorption of water, and RAAS maintains the
osmolarity of the blood by stimulating Na+ reabsorption.
C) ADH
and RAAS work antagonistically; ADH stimulates water reabsorption
during dehydration and RAAS causes increased excretion of water when
it is in excess in body fluids.
D) both stimulate the adrenal
gland to secrete aldosterone, which increases both blood volume and
pressure via its receptors in the urinary bladder.
E) by
combining at the receptor sites of proximal tubule cells, where
reabsorption of essential nutrients takes place. | |
front 60 Use the following structural formulas to identify the following items
60) Which of the following is excreted readily by aquatic
animals because of its high solubility in the respiratory medium?
A) A
B) B
C) C
D) D
E) E | |
front 61 Use the following structural formulas to identify the following items
61) Which of the following is synthesized by mammals, most
amphibians, sharks, and some bony fishes, and has lower toxicity than
its nitrogenous substrate?
A) A
B) B
C) C
D) D
E) E | |
front 62 Use the following structural formulas to identify the following items
62) Which of the following is excreted as a paste by land
snails, insects, birds, and many reptiles, because of its solubility
and toxicity properties?
A) A
B) B
C) C
D) D
E) E | |
front 63 63) In a laboratory experiment with three groups of students, one
group drinks pure water, a second group drinks an equal amount of
beer, and a third group drinks an equal amount of concentrated salt
solution, all during the same time period. Their urine production is
monitored for several hours. Which groups are expected to have the
greatest and least amounts of urine, respectively?
A) Beer
drinkers have the most; salt solution drinkers have the least.
B) Salt solution drinkers have the most; water drinkers have the
least.
C) Water drinkers have the most; beer drinkers have the
least.
D) Beer drinkers have the most; water drinkers have the
least.
E) There will be no significant difference between these groups. | |
front 64 64) Unlike an earthworm's metanephridia, a mammalian nephron
A)
is intimately associated with a capillary network.
B) forms
urine by changing fluid composition inside a tubule.
C)
functions in both osmoregulation and excretion.
D) receives
filtrate from blood instead of coelomic fluid.
E) has a
transport epithelium. | |
front 65 65) Which process in the nephron is least selective?
A)
filtration
B) reabsorption
C) active transport
D)
secretion
E) salt pumping by the loop of Henle | |
front 66 66) Which of the following animals generally has the lowest volume of
urine production?
A) a vampire bat
B) a salmon in fresh
water
C) a marine bony fish
D) a freshwater bony fish
E) a shark inhabiting freshwater Lake Nicaragua | |
front 67 67) The high osmolarity of the renal medulla is maintained by all of
the following except
A) diffusion of salt from the thin segment
of the ascending limb of the loop of Henle.
B) active transport
of salt from the upper region of the ascending limb.
C) the
spatial arrangement of juxtamedullary nephrons.
D) diffusion of
urea from the collecting duct.
E) diffusion of salt from the
descending limb of the loop of Henle. | |
front 68 68) Natural selection should favor the highest proportion of
juxtamedullary nephrons in which of the following species?
A) a
river otter
B) a mouse species living in a tropical rain forest
C) a mouse species living in a temperate broadleaf forest
D) a mouse species living in a desert
E) a beaver | |
front 69 69) African lungfish, which are often found in small stagnant pools
of fresh water, produce urea as a nitrogenous waste. What is the
advantage of this adaptation?
A) Urea takes less energy to
synthesize than ammonia.
B) Small stagnant pools do not provide
enough water to dilute the toxic ammonia.
C) The highly toxic
urea makes the pool uninhabitable to potential competitors.
D)
Urea forms an insoluble precipitate.
E) Urea makes lungfish
tissue hypoosmotic to the pool. | |
