956
CHAPTER 48—REGULATING THE INTERNAL ENVIRONMENT
MULTIPLE CHOICE
1. If you were stranded in the Sahara Desert with very little water, you would likely die as a result of
a.
dehydration.
b.
hyperthermia.
c.
hypothermia.
d.
dehydration and hyperthermia.
e.
dehydration. hyperthermia and hypothermia.
2. Osmoregulation is the control of
a.
the internal environment.
b.
temperature.
c.
metabolic wastes.
d.
water and ion balance.
e.
hyperthermia.
3. Osmolarity is the outcome of the
a.
total solute plus solvent concentration in a solution.
b.
total solvent concentration in a solution.
c.
ratio of solvent to solute in a solution.
d.
total solute concentration in a solution.
e.
ratio of solute to solvent in a solution.
4. Suppose that you have a cell with a membrane that is permeable to water but not to Na+ or Cl− or any
other solute. There is more NaCl outside the cell than inside the cell, and the osmolarity of the cell is
higher than that of the solution surrounding the cell. Which of the following should occur?
a.
Overall, the cell should lose water.
b.
Overall, the cell should take up water, Na+, and Cl−.
c.
Overall, the cell should take up water.
d.
Overall, the cell should take up water and lose Na+ and Cl−.
e.
Overall, the cell should lose water and take up Na+ and Cl−.
5. The typical osmolarity of most body fluids in humans and other mammals is
a.
~5 mOsm/L.
b.
~225 mOsm/L.
c.
~300 mOsm/L.
d.
~1000 mOsm/L.
e.
~1500 mOsm/L.
6. Fresh water has an osmolarity of
a.
~5 mOsm/L.
b.
~225 mOsm/L.
c.
~300 mOsm/L.
d.
~1000 mOsm/L.
e.
~1500 mOsm/L.
7. The typical osmolarity of body fluids in most freshwater invertebrates is
a.
~5 mOsm/L.
b.
~225 mOsm/L.
c.
~300 mOsm/L.
d.
~1000 mOsm/L.
e.
~1500 mOsm/L.
8. The typical osmolarity of body fluids in most marine invertebrates is
a.
~5 mOsm/L.
b.
~225 mOsm/L.
c.
~300 mOsm/L.
d.
~1000 mOsm/L.
e.
~1500 mOsm/L.
9. Seawater typically has an osmolarity of
a.
~5 mOsm/L.
b.
~225 mOsm/L.
c.
~300 mOsm/L.
d.
~1000 mOsm/L.
e.
~1500 mOsm/L.
10. Which of the following are typically osmoconformers?
a.
freshwater teleost fishes
b.
sharks
c.
birds
d.
marine teleost fishes
e.
freshwater invertebrates
11. In all but the simplest animals, osmoregulation and excretion is carried out using tubules that are
a.
specialized blood vessels.
b.
part of the lining of the digestive tract.
c.
modifications of the respiratory and digestive systems.
d.
associated with the surface of the skin.
e.
formed from transport epithelium.
12. The nonselective movement of water and a number of solutes into excretory system tubules is
a.
reabsorption.
b.
release.
c.
filtration.
d.
secretion.
e.
diffusion.
13. The exiting of wastes from the excretory system is
a.
reabsorption.
b.
release.
c.
filtration.
d.
secretion.
e.
diffusion.
14. The selective movement of specific small molecules and ions into excretory system tubules is
a.
reabsorption.
b.
release.
c.
filtration.
d.
secretion.
e.
diffusion.
15. The movement of some molecules and ions out of excretory system tubules and back into body fluids
is
a.
reabsorption.
b.
release.
c.
filtration.
d.
secretion.
e.
diffusion.
16. Suppose sugar is taken out of an excretory system tubule and back into the blood. This would be an
example of
a.
reabsorption.
b.
release.
c.
filtration.
d.
secretion.
e.
diffusion.
17. Which of the following is the main form of nitrogenous wastes released by aquatic invertebrates to
their environment?
a.
nitrate
b.
ammonia
c.
uric acid
d.
amino acids
e.
urea
18. Which of the following is the main form of nitrogenous wastes released by mammals to their
environment?
a.
nitrate
b.
ammonia
c.
uric acid
d.
amino acids
e.
urea
19. Which of the following is the main form of nitrogenous wastes released by birds to their environment?
a.
nitrate
b.
ammonia
c.
uric acid
d.
amino acids
e.
urea
20. Compared to uric acid, using urea as the main form of nitrogenous waste requires
a.
more energy and water.
b.
less energy and water.
c.
more energy and less water.
d.
the same amount of energy and water.
e.
less energy and more water.
21. The relatively simple excretory system used by flatworms consists of tubules called
a.
nephrons.
b.
hepatic tubules.
c.
metanephridia.
d.
Malpighian tubules.
e.
protonephridia.
22. The smallest branches of ____ end with a large flame cell.
a.
nephrons
b.
hepatic tubules
c.
metanephridia
d.
Malpighian tubules
e.
protonephridia
23. Protonephridia are found in
a.
annelids.
b.
mammals.
c.
flatworms.
d.
insects.
e.
adult mollusks.
24. The excretory system used by most annelids and adult mollusks consists of tubules called
a.
nephrons.
b.
hepatic tubules.
c.
metanephridia.
d.
Malpighian tubules.
e.
protonephridia.
25. Metanephridia are found in
a.
annelids.
b.
mammals.
c.
flatworms.
d.
insects.
e.
larval mollusks.
26. You examine an animal and find that it has excretory tubules that have a closed proximal end
immersed in hemolymph and a distal end that empties into the gut. Which term should you use to
describe these tubules?
a.
nephrons
b.
hepatic tubules
c.
metanephridia
d.
Malpighian tubules
e.
protonephridia
27. Malpighian tubules are found in
a.
annelids.
b.
mammals.
c.
flatworms.
d.
insects.
e.
larval mollusks.
28. Nitrogenous waste is excreted from Malpighian tubules mainly in the form of
a.
nitrate.
b.
ammonia.
c.
uric acid.
d.
amino acids.
e.
urea.
29. True kidneys have tubules called
a.
nephrons.
b.
hepatic tubules.
c.
metanephridia.
d.
Malpighian tubules.
e.
protonephridia.
30. Nephrons are found in
a.
annelids.
b.
mammals.
c.
flatworms.
d.
insects.
e.
adult mollusks.
31. The descending segment of the longest loops of Henle descend into the
a.
renal pelvis.
b.
renal cortex.
c.
Bowman’s capsule.
d.
collecting ducts.
e.
renal medulla.
32. The tube through which urine leaves the urinary bladder is the
a.
collecting duct.
b.
urethra.
c.
renal pelvis.
d.
ureter.
e.
renal vein.
33. In mammals, the filtrate leaves the blood by exiting from the
a.
efferent arteriole.
b.
peritubular capillaries.
c.
renal artery.
d.
afferent arteriole.
e.
glomerulus.
34. In mammals, the glomerulus is located within the
a.
distal convoluted tubule.
b.
Bowman’s capsule.
c.
descending segment of the loop of Henle.
d.
proximal convoluted tubule.
e.
ascending segment of the loop of Henle.
35. In mammals, urine drains out of the ____ into a collecting duct.
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
36. Because it has no aquaporins, water is generally trapped in the ____ in mammals.
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
37. As filtrate moves through the ____ in mammals it generally undergoes a dramatic decrease in
osmolarity.
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
38. Which of the following excretory tubule segments in mammals allows water to exit but does not allow
ions or urea to exit?
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
39. In which of the following excretory tubule segments in mammals does about 65 percent of the water
from the filtrate get reabsorbed?
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
40. In which of the following excretory tubule segments in mammals does essentially all of the glucose
and amino acids from the filtrate get reabsorbed?
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
41. Which of the following segments of the mammalian nephron receives the filtrate first?
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
42. Molecules and ions reabsorbed from the nephron reenter the blood at the
a.
efferent arteriole.
b.
peritubular capillaries.
c.
renal artery.
d.
afferent arteriole.
e.
glomerulus.
43. In a typical adult human about 180 L of fluid leaves the blood as filtrate each day, and ____ is
reabsorbed.
a.
~50 percent
b.
~65 percent
c.
~80 percent
d.
~90 percent
e.
over 99 percent
44. Aquaporins are
a.
cells that are specialized for water transport.
b.
transport channels for water.
c.
the entry point of filtrate into a nephron.
d.
transport channels for ions.
e.
the exit channel for urine out of a nephron.
45. Which of the following excretory tubule segments in mammals consumes the most ATP?
a.
distal convoluted tubule
b.
Bowman’s capsule
c.
descending segment of the loop of Henle
d.
proximal convoluted tubule
e.
ascending segment of the loop of Henle
46. Where in the mammalian kidney should you expect to find cells with the highest concentration of
osmolytes such as sorbitol?
a.
renal pelvis
b.
renal cortex
c.
Bowman’s capsule
d.
collecting ducts
e.
renal medulla
47. The kangaroo rat gets the bulk of its water from
a.
drinking liquids.
b.
absorption through its skin.
c.
ingesting food.
d.
oxidative reactions in its cells.
e.
reuptake of water from urine.
48. The urine of marine mammals is ____ when compared to ____.
a.
hypoosmotic; seawater
b.
hypoosmotic; their body fluids
c.
hyperosmotic; seawater
d.
isoosmotic; their body fluids
e.
isoosmotic; seawater
49. The osmotic response element discovered by Ferraris and her colleagues came from the promoter for
a.
hexokinase.
b.
sorbitol dehydrogenase.
c.
aldose reductase.
d.
luciferase.
e.
sorbitase.
50. Suppose that the osmotic response element is in a promoter joined to the coding region of luciferase,
and this composite gene is in cultured renal medulla cells. The cells should glow when they are placed
in a medium that is ____ to the cells.
a.
hyperosmotic
b.
hypoosmotic
c.
hypoosmotic or isoosmotic
d.
isotoosmotic
e.
hyperosmotic or isotoosmotic