Deck 44: Osmoregulation and Excretion

Question 1

A human who has no access to fresh water but is forced to drink sea water 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.

Answer 1

B

Question 2

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 sea water, such as a bird living in a marine environment.
C)lots of sea water, 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.

Answer 2

A

Question 3

The body fluids of an osmoconformer would be ________ with its ________ environment.

A)hyperosmotic; freshwater
B)isotonic; freshwater
C)hyperosmotic; saltwater
D)isoosmotic; saltwater
E)hypoosmotic; saltwater

Answer 3

D

Question 4

Organisms categorized as osmoconformers are most likely

A)found in freshwater lakes and streams.
B)marine.
C)amphibious.
D)found in arid terrestrial environments.
E)found in terrestrial environments with adequate moisture.

Question 5

Which nitrogenous waste has the greatest number of nitrogen atoms?

A)ammonia
B)ammonium ions
C)urea
D)uric acid

Question 6

Compared to the sea water around them, most marine invertebrates are

A)hyperosmotic.
B)hypoosmotic.
C)isoosmotic.
D)hyperosmotic and isoosmotic.
E)hypoosmotic and isoosmotic.

Question 7

Which of the following animals is most likely to excrete ammonia?

A)painted turtle
B)white-tailed deer
C)nurse shark
D)yellow perch
E)bullfrog

Question 8

After mistakenly adding salt to your freshwater tank, all of your fish died because

A)they were isosmotic to the saltwater.
B)they are a stenohaline species.
C)they are a diadromous species.
D)they are a euryhaline species.
E)they were hyperosmotic to the saltwater.

Question 9

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 sea water.
C)via active transport of water across the cells on their gills.
D)by water diffusion from sea water, which is hyperosmotic to the fluids in their cells.
E)by selective transport of water molecules across the wall of the gut.

Question 10

The porbeagle shark (Lamana nasus), found on the continental shelf between Newfoundland and Labrador and Gulf of Maine, excretes ________ which is produced in the ________.

A)urea, gall bladder
B)ammonia, kidney
C)urea, kidney
D)ammonia, liver
E)urea, liver

Question 11

In its native habitat, the sea lamprey (Petromyzon marinus)has a diadromous lifecycle. When preparing to migrate from fresh water to the sea, the lamprey must metamorphose so that it can survive the change in salinity. To achieve osmoregulation in the sea, the lamprey must

A)decrease water uptake and decrease solute excretion.
B)increase water uptake and increase solute excretion.
C)decrease water uptake and increase solute excretion.
D)increase water uptake and decrease solute excretion.
E)decrease water uptake and decrease solute absorption.

Question 12

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 sea water and secrete excess ions through their kidneys only.
C)drink sea water 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.

Question 13

A necropsy (postmortem analysis)of a marine sea star that died after it was mistakenly placed in fresh water would likely show that it died because

A)it was stressed and needed more time to acclimate to the new conditions.
B)it was so hyperosmotic to the fresh water that it could not osmoregulate.
C)the sea star's kidneys could not handle the change in ionic content presented by the fresh water.
D)its contractile vacuoles ruptured.
E)its cells dehydrated and lost the ability to metabolize.

Question 14

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

Question 15

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.

Question 16

The necropsy (postmortem analysis)of a freshwater fish that died after being placed accidentally in salt water 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.

Question 17

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.

Question 18

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.

Question 19

The fluid with the highest osmolarity is

A)distilled water.
B)plasma in birds.
C)plasma in mammals.
D)sea water in a tidal pool.
E)estuarine water.

Question 20

Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to sea water, 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.

Question 21

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

Question 22

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.

Question 23

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.

Question 24

The primary nitrogenous waste excreted by birds is

A)ammonia.
B)nitrate.
C)nitrite.
D)urea.
E)uric acid.

Question 25

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.

Question 26

Excretory structures known as protonephridia are present in

A)flatworms.
B)earthworms.
C)insects.
D)vertebrates.
E)cnidarians.

Question 27

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.

Question 28

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.

Question 29

The nitrogenous waste that requires the most energy to produce is

A)ammonia.
B)ammonium.
C)urea.
D)uric acid.

Question 30

Which nitrogenous waste requires hardly any water for its excretion?

A)amino acids
B)urea
C)uric acid
D)ammonia
E)nitrogen gas

Question 31

Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal.

A)metanephridium-flatworm
B)Malpighian tubule-frog
C)kidney-insect
D)flame bulb-snake
E)direct cellular exchange-marine invertebrate

Question 32

Excretory organs known as Malpighian tubules are present in

A)earthworms.
B)flatworms.
C)insects.
D)jellyfish.
E)sea stars.

Question 33

Among the following choices, the most concentrated urine is excreted by

A)frogs.
B)kangaroo rats.
C)humans.
D)desert tortoises.
E)birds.

Question 34

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.

Question 35

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.

Question 36

The osmoregulatory/excretory system of an earthworm is based on the operation of

A)protonephridia.
B)metanephridia.
C)Malpighian tubules.
D)nephrons.
E)ananephredia.

Question 37

Freshwater flatworms produce 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.

Question 38

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.

Question 39

The osmoregulatory/excretory system of an insect is based on the operation of

A)protonephridia.
B)metanephridia.
C)Malpighian tubules.
D)nephrons.
E)ananephredia.

Question 40

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.

Question 41

If ATP production in a human kidney were 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.

Question 42

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.

Question 43

If the concentration of glucose in the blood flowing through the kidneys is within normal range, which of the following statements is correct?

A)The nephron pumps glucose into the collecting duct.
B)Most glucose within the nephron tubule is reabsorbed by the blood.
C)The Bowman's capsule secretes glucose back into the blood.
D)No glucose passes from the glomerulus to the Bowman's capsule.
E)Most glucose that passes from the blood into the nephron tubule remains in the urine and is excreted.

Question 44

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.

Question 45

It is wise to drink 2 glasses of water for every 1 alcoholic beverage consumed. This is because

A)alcohol can increase the release of aldosterone.
B)alcohol can disrupt the release of ADH.
C)alcohol increases the release of ADH.
D)alcohol disrupts the function of the thalamus.
E)alcohol disrupts the function of RAAS.

Question 46

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.

Question 47

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.

Question 48

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.

Question 49

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.

Question 50

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.

Question 51

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.

Question 52

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.

Question 53

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.

Question 54

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.

Question 55

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.

Question 56

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 gases.

Question 57

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.

Question 58

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.

Question 59

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.

Question 60

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.

Question 61

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.

Question 62

Use the following structural formulas to identify the following items.

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

Question 63

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.

Question 64

Natural selection should favour 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

Question 65

Use the following information to answer the next few questions.
While spelunking, you have discovered a new species deep inside the cave. This animal does not have easy access to water. It has a dense coat of fur, a four-chambered heart, and a closed circulatory system.
Which excretory system modification do you expect to find?

A)absent juxtamedullary nephron
B)short loop of Henle, excreting dilute urine
C)long loop of Henle extending deep into the medulla
D)extensive capillary network on the metanephridia
E)very long flame bulbs in the protonephridia

Question 66

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

Question 67

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.

Question 68

Use the following information to answer the next few questions.
While spelunking, you have discovered a new species deep inside the cave. This animal does not have easy access to water. It has a dense coat of fur, a four-chambered heart, and a closed circulatory system.
You expect the animal's urine to be

A)isoosmotic to body fluids.
B)hypoosmotic to body fluids.
C)hypotonic to body fluids.
D)hyperosmotic to body fluids.
E)isotonic to body fluids.

Question 69

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)ADH and RAAS combine at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place.

Question 70

Use the following structural formulas to identify the following items.

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

Question 71

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

Question 72

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.

Question 73

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.

Question 74

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.

Question 75

Use the following information to answer the next few questions.
After a long week, you join a few friends at a local pub to enjoy a meal and have a few beers. After a few hours and several beers, you find yourself to be quite thirsty.
You feel thirsty because

A)you ate very salty pub food.
B)you abstained from alcohol and drank water.
C)you drank a few beers.
D)you ate salty pub food and drank a few beers.
E)you drank water and ate salty pub food.

Question 76

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.

Question 77

Use the following structural formulas to identify the following items.

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

Question 78

Use the following information to answer the next few questions.
After a long week, you join a few friends at a local pub to enjoy a meal and have a few beers. After a few hours and several beers, you find yourself to be quite thirsty.
The hormone responsible for regulating blood osmolarity after ingesting a salty meal is

A)ADH.
B)aldosterone.
C)ANP.
D)renin.
E)angiotensin.

Question 79

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.