Question 1

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because ________.

Accepted Answer

A)  absorptive processes taking place in the loop of Henle are hormonally regulated 
B)  differential permeabilities of ascending and descending limbs of the loop of Henle are important in establishing an osmotic gradient 
C)  the loop of Henle plays an important role in detoxification 
D)  additional filtration takes place along the loop of Henle 
A)  absorptive processes taking place in the loop of Henle are hormonally regulated 
B)  differential permeabilities of ascending and descending limbs of the loop of Henle are important in establishing an osmotic gradient 
C)  the loop of Henle plays an important role in detoxification 
D)  additional filtration takes place along the loop of Henle B

Question 2

An examination of a freshwater fish that died after being placed accidentally in saltwater would likely show that ________.

Accepted Answer

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 
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 A

Question 3

The high osmolarity of the renal medulla is maintained by all of the following except

Accepted Answer

A)  active transport of salt from the upper region of the ascending limb. 
B)  the spatial arrangement of juxtamedullary nephrons. 
C)  diffusion of urea from the collecting duct. 
D)  diffusion of salt from the descending limb of the loop of Henle. 
A)  active transport of salt from the upper region of the ascending limb. 
B)  the spatial arrangement of juxtamedullary nephrons. 
C)  diffusion of urea from the collecting duct. 
D)  diffusion of salt from the descending limb of the loop of Henle. D

Question 4

An examination of a marine sea star that had died after it was mistakenly placed in fresh water would likely show that it died because ________.

Accepted Answer

A)  it was stressed and needed more time to acclimate to the new conditions 
B)  it was so hypertonic to the fresh water that it could not osmoregulate 
C)  its kidney had ruptured 
D)  its cells dehydrated and lost the ability to metabolize 
A)  it was stressed and needed more time to acclimate to the new conditions 
B)  it was so hypertonic to the fresh water that it could not osmoregulate 
C)  its kidney had ruptured 
D)  its cells dehydrated and lost the ability to metabolize

Question 5

A human who has no access to fresh water but is forced to drink seawater instead will ________.

Accepted Answer

A)  produce excessive antidiuretic hormone to remove more water but hold back salts 
B)  passively excrete excess water in order to remove the high concentration of ingested salt 
C)  release atrial natriuretic peptide to decrease blood pressure 
D)  risk becoming overhydrated within twelve hours 
A)  produce excessive antidiuretic hormone to remove more water but hold back salts 
B)  passively excrete excess water in order to remove the high concentration of ingested salt 
C)  release atrial natriuretic peptide to decrease blood pressure 
D)  risk becoming overhydrated within twelve hours

Question 6

Salmon eggs hatch in fresh water. The fish then migrate to the ocean (a hypertonic solution) and, after several years of feeding and growing, return to fresh water to breed. How can these organisms make the transition from fresh water to ocean water and back to fresh water?

Accepted Answer

A)  The rectal gland functions in the ocean water, and chloride cells function in fresh water. 
B)  The salt transport mechanisms of the gill epithelia change during migration. 
C)  Salmon in fresh water excrete concentrated urine, and salmon in salt water secrete dilute urine. 
D)  Their metabolism changes in salt water to degrade electrolytes. 
A)  The rectal gland functions in the ocean water, and chloride cells function in fresh water. 
B)  The salt transport mechanisms of the gill epithelia change during migration. 
C)  Salmon in fresh water excrete concentrated urine, and salmon in salt water secrete dilute urine. 
D)  Their metabolism changes in salt water to degrade electrolytes.

Question 7

The force driving simple diffusion is ________, while the energy source for active transport is ________.

Accepted Answer

A)  the concentration gradient; ADP 
B)  the concentration gradient; ATP 
C)  transmembrane pumps; electron transport 
D)  phosphorylated protein carriers; ATP 
A)  the concentration gradient; ADP 
B)  the concentration gradient; ATP 
C)  transmembrane pumps; electron transport 
D)  phosphorylated protein carriers; ATP

Question 8

Birds secrete uric acid as their nitrogenous waste because uric acid ________.

Accepted Answer

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)  can be reused by birds as a protein source 
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)  can be reused by birds as a protein source

Question 9

Studies of cricket Malpighian tubules revealed that potassium ions accumulated inside the tubule, moving against the potassium concentration gradient. How would you expect the movement of water to be influenced by the distribution of potassium ions?

Accepted Answer

A)  Water would be forced out of the lumen of the Malpighian tubules through an osmotic gradient. 
B)  The potassium gradient would have no effect on water movement. 
C)  There would be a net movement of water into the lumen of the tubules. 
D)  Water would be conserved, forming a hypertonic solution in the Malpighian tubules. 
A)  Water would be forced out of the lumen of the Malpighian tubules through an osmotic gradient. 
B)  The potassium gradient would have no effect on water movement. 
C)  There would be a net movement of water into the lumen of the tubules. 
D)  Water would be conserved, forming a hypertonic solution in the Malpighian tubules.

Question 10

Increased antidiuretic hormone (ADH) secretion is likely after ________.

Accepted Answer

A)  drinking lots of pure water 
B)  sweating-induced dehydration increases plasma osmolarity 
C)  eating a small sugary snack 
D)  blood pressure becomes abnormally high 
A)  drinking lots of pure water 
B)  sweating-induced dehydration increases plasma osmolarity 
C)  eating a small sugary snack 
D)  blood pressure becomes abnormally high

Question 11

Like other osmoregulatory animals that live in marine environments, sharks maintain tissue concentrations of sodium, potassium, and chloride that are hypoosmotic to the seawater. In contrast to the bony marine fishes, however, sharks do not need to drink seawater. Why?

Accepted Answer

A)  High urea and trimethylamine oxide concentrations keep shark tissues slightly hyperosmotic relative to seawater, so water is absorbed passively. 
B)  Sodium, chloride, and potassium do not influence water balance in shark tissues. 
C)  Shark blood is hypotonic to the surrounding tissues, so water always moves passively into the tissue from the blood. 
D)  Sharks excrete large quantities of salt through their gills in exchange for water 
A)  High urea and trimethylamine oxide concentrations keep shark tissues slightly hyperosmotic relative to seawater, so water is absorbed passively. 
B)  Sodium, chloride, and potassium do not influence water balance in shark tissues. 
C)  Shark blood is hypotonic to the surrounding tissues, so water always moves passively into the tissue from the blood. 
D)  Sharks excrete large quantities of salt through their gills in exchange for water

Question 12

Urea is ________.

Accepted Answer

A)  insoluble in water 
B)  the primary nitrogenous waste product of humans 
C)  the primary nitrogenous waste product of most birds 
D)  the primary nitrogenous waste product of most aquatic invertebrates 
A)  insoluble in water 
B)  the primary nitrogenous waste product of humans 
C)  the primary nitrogenous waste product of most birds 
D)  the primary nitrogenous waste product of most aquatic invertebrates

Question 13

Urea is produced in the ________.

Accepted Answer

A)  liver from NH₃ and carbon dioxide 
B)  liver from glycogen 
C)  kidneys from glycerol and fatty acids 
D)  bladder from uric acid and water 
A)  liver from NH₃ and carbon dioxide 
B)  liver from glycogen 
C)  kidneys from glycerol and fatty acids 
D)  bladder from uric acid and water

Question 14

The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of ________.

Accepted Answer

A)  protonephridia 
B)  metanephridia 
C)  Malpighian tubules 
D)  nephrons 
A)  protonephridia 
B)  metanephridia 
C)  Malpighian tubules 
D)  nephrons

Question 15

Unlike an earthworm's metanephridia, a mammalian nephron

Accepted Answer

A)  is intimately associated with a capillary network. 
B)  functions in both osmoregulation and excretion. 
C)  receives filtrate from blood instead of coelomic fluid. 
D)  has a transport epithelium. 
A)  is intimately associated with a capillary network. 
B)  functions in both osmoregulation and excretion. 
C)  receives filtrate from blood instead of coelomic fluid. 
D)  has a transport epithelium.

Question 16

After drinking alcoholic beverages, increased urine excretion is the result of ________.

Accepted Answer

A)  increased aldosterone production 
B)  increased blood pressure 
C)  inhibited secretion of antidiuretic hormone (ADH) 
D)  increased reabsorption of water in the proximal tubule 
A)  increased aldosterone production 
B)  increased blood pressure 
C)  inhibited secretion of antidiuretic hormone (ADH) 
D)  increased reabsorption of water in the proximal tubule

Question 17

Animals have adapted different mechanisms for excreting nitrogenous waste products. Which of the following are selective pressures that likely influence which mechanism an animal uses?
I.the amount of water available in the animal's habitat
II.the energy needs of the animal
III.the temperature of the animal's environment

Accepted Answer

A)  only I and III 
B)  only II and III 
C)  only I and II 
D)  I, II, and III 
A)  only I and III 
B)  only II and III 
C)  only I and II 
D)  I, II, and III

Question 18

Use the following figure to answer the question.
 
Selective secretion of toxins and drugs takes place in the structure labeled ________.

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D

Question 19

Studies of cricket Malpighian tubules revealed that potassium ions accumulated inside the tubule, moving against the potassium concentration gradient. Based on the information, what can you infer about the mechanism of potassium transport?

Accepted Answer

A)  Potassium transport is a passive process. 
B)  Movement of potassium into the lumen of the Malpighian tubules is an energy-requiring process. 
C)  Potassium moves out of the tubules at a faster rate than it moves into the lumen of the tubules. 
D)  Sodium ions will follow potassium ions. 
A)  Potassium transport is a passive process. 
B)  Movement of potassium into the lumen of the Malpighian tubules is an energy-requiring process. 
C)  Potassium moves out of the tubules at a faster rate than it moves into the lumen of the tubules. 
D)  Sodium ions will follow potassium ions.

Question 20

In which of the following species should natural selection favor the highest proportion of juxtamedullary nephrons?

Accepted Answer

A)  a river otter 
B)  a mouse species living in a temperate broadleaf forest 
C)  a mouse species living in a desert 
D)  a beaver 
A)  a river otter 
B)  a mouse species living in a temperate broadleaf forest 
C)  a mouse species living in a desert 
D)  a beaver

Exam 44: Osmoregulation and Excretion

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because ________.

An examination of a freshwater fish that died after being placed accidentally in saltwater would likely show that ________.

The high osmolarity of the renal medulla is maintained by all of the following except

An examination of a marine sea star that had died after it was mistakenly placed in fresh water would likely show that it died because ________.

A human who has no access to fresh water but is forced to drink seawater instead will ________.

Salmon eggs hatch in fresh water. The fish then migrate to the ocean (a hypertonic solution) and, after several years of feeding and growing, return to fresh water to breed. How can these organisms make the transition from fresh water to ocean water and back to fresh water?

The force driving simple diffusion is ________, while the energy source for active transport is ________.

Birds secrete uric acid as their nitrogenous waste because uric acid ________.

Studies of cricket Malpighian tubules revealed that potassium ions accumulated inside the tubule, moving against the potassium concentration gradient. How would you expect the movement of water to be influenced by the distribution of potassium ions?

Increased antidiuretic hormone (ADH) secretion is likely after ________.

Like other osmoregulatory animals that live in marine environments, sharks maintain tissue concentrations of sodium, potassium, and chloride that are hypoosmotic to the seawater. In contrast to the bony marine fishes, however, sharks do not need to drink seawater. Why?

Urea is ________.

Urea is produced in the ________.

The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of ________.

Unlike an earthworm's metanephridia, a mammalian nephron

After drinking alcoholic beverages, increased urine excretion is the result of ________.

Use the following figure to answer the question. Selective secretion of toxins and drugs takes place in the structure labeled ________.

Studies of cricket Malpighian tubules revealed that potassium ions accumulated inside the tubule, moving against the potassium concentration gradient. Based on the information, what can you infer about the mechanism of potassium transport?

In which of the following species should natural selection favor the highest proportion of juxtamedullary nephrons?

Evolution, the Themes of Biology, and Scientific Inquiry

The Chemical Context of Life

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Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

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Membrane Structure and Function

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Gene Expression: From Gene to Protein

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Descent with Modification: A Darwinian View of Life

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