Chapter 44 Questions Flashcards
Blood flukes are parasitic flatworms that live in the bloodstream of the host. The worm’s interstitial fluids are isoosmotic to the host’s blood, so which of these is/are true?
- The worms lack flame bulbs or have nonfunctional flame bulbs.
- The worms have flame bulbs that are mostly active in performing osmoregulation.
- The worms have flame bulbs that eliminate nitrogenous wastes.
- The worms have flame bulbs whose role is to eliminate excess water that enters the worm by osmosis.
a. 1 only
b. 3 only
c. 2 and 3
d. 2 and 4
e. 3 and 4
b. 3 only
Under which circumstance should reabsorption of water from the kidney filtrate back into the bloodstream be most effective?
a. if neither ADH nor aldosterone is present in circulation
b. if both ADH and aldosterone are present in circulation
c. if ADH, but not aldosterone, is present in circulation
d. if aldosterone, but not ADH, is present in circulation
e. if renin, angiotensin II, and aldosterone are present in circulation, but not ADH
b. if both ADH and aldosterone are present in circulation
Animals that can produce exceptionally concentrated urine should be expected to have nephrons with longer _____.
- descending limbs of the loops of Henle
- ascending limbs of the loops of Henle
- distal tubules
- proximal tubules
a. 1 only
b. 3 only
c. 1 and 2
d. 1 and 4
e. all four of these
c. 1 and 2
Which two solutes become more abundant in the kidney medulla’s interstitial fluid as one progresses deeper into the medulla, and what is the significance of these two gradients?
a. urea and NaCl; interstitial fluids there become isoosmotic to blood
b. NaCl and KCl; this promotes maximal chloride ion retention
c. HCO3– and H+; this produces pH-neutral interstitial fluids
d. urea and KCl; less urea is actually excreted than is possible
e. urea and NaCl; this promotes better retention of water
e. urea and NaCl; this promotes better retention of water
In the kidneys, which hormone is most effective at causing increased numbers of aquaporins to be present in collecting duct epithelia, and what is the source of this hormone?
a. ADH; posterior pituitary gland
b. aldosterone; adrenal medulla
c. renin; kidneys
d. aldosterone; adrenal cortex
e. ADH; kidneys
a. ADH; posterior pituitary gland
Osmoregulation is the _____.
a. enhancement or amplification of an effect by its own influence on the process that gives rise to it
b. movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy
c. process by which animals control solute concentrations and balance water gain and loss
d. process that cells and viruses use to regulate the way that the information in genes is turned into gene products
c. process by which animals control solute concentrations and balance water gain and loss
Which of the following is not associated with the production of urine?
a. proximal tubule
b. loop of Henle
c. distal tubule
d. collecting duct
e. Malpighian tubules
e. Malpighian tubules
What effect would you expect the drug furosemide, which blocks transport of Na+ and Cl– in the ascending limb of the loop of Henle, to have on urine volume?
a. increase urine volume
b. decrease urine volume
c. no effect on urine volume
a. increase urine volume
Which of the following is not an adaptation of the vertebrate kidney to diverse environments?
a. In mammals, the juxtamedullary nephrons can concentrate urine, allowing mammals to eliminate waste without losing excess water.
b. In birds, the nephrons have loops of Henle that don’t extend as far into the medulla as those of mammals.
c. In reptiles, the kidneys have only cortical nephrons and produce urine that is iso- or hypoosmotic to body fluid.
d. Freshwater fishes have kidneys containing many nephrons and produce filtrate at a high rate.
e. Marine bony fishes have more and larger nephrons than freshwater fishes, and their nephrons also lack a proximal tubule.
e. Marine bony fishes have more and larger nephrons than freshwater fishes, and their nephrons also lack a proximal tubule.
Which of the following statements about atrial natriuretic peptide (ANP) is incorrect?
a. The walls of the heart release ANP in response to a decrease in blood volume and pressure.
b. ANP inhibits the release of renin from the juxtaglomerular apparatus (JGA).
c. ANP inhibits the reabsorption of NaCl by the collecting ducts.
d. ANP reduces aldosterone release from the adrenal glands.
e. The regulatory role of ANP is under investigation.
a. The walls of the heart release ANP in response to a decrease in blood volume and pressure.
How does the renin-angiotensinogen-aldosterone system (RAAS) respond in the case of an excessive loss of both salt and body fluids?
a. It activates the hormone atrial natriuretic peptide, which increases blood volume and pressure.
b. It responds to the drop in blood volume and pressure by increasing water and Na+ reabsorption.
c. It stimulates the production of ADH in the posterior pituitary, lowering blood Na+ concentration.
d. It inhibits the production of angiotensin converting enzyme (ACE), suppressing the production of angiotensin II.
b. It responds to the drop in blood volume and pressure by increasing water and Na+ reabsorption.
Why did mRNA from a diabetes insipidus patient with two mutant aquaporin-2 alleles produce nonfunctional aquaporin water channels when expressed in frog oocytes?
a. Oocytes do not have aquaporin water channels.
b. Foreign mRNA cannot be translated into functional protein in frog oocytes.
c. Since frogs are aquatic, they are isoosmotic to their environment and unresponsive to aquaporin water channels.
d. The water channels were nonfunctional because they were translated from mRNA transcribed from mutant aquaporin genes.
d. The water channels were nonfunctional because they were translated from mRNA transcribed from mutant aquaporin genes.
Which organism, a human or a kangaroo rat (a desert rodent), derives a greater percentage of its total water from metabolism? Which do you think has a longer loop of Henle? Table. a. kangaroo rat; kangaroo rat b. human; kangaroo rat c. kangaroo rat; human d. human; human
a. kangaroo rat; kangaroo rat
Which of the following statements comparing osmoregulation in marine and freshwater bony fishes is incorrect?
a. Freshwater fishes excrete salt ions and larger amounts of water in dilute urine than marine fishes.
b. Freshwater fishes take in salt ions by means of their gills, while marine fishes excrete salt ions from their gills.
c. Freshwater fishes gain osmotic water through their gills and body surfaces, while marine fishes lose osmotic water the same way.
d. Freshwater fishes drink seawater to obtain water and salt ions, while marine fishes drink almost none.
d. Freshwater fishes drink seawater to obtain water and salt ions, while marine fishes drink almost none.
Which animals are being studied as examples of an adaptation called anhydrobiosis?
a. tardigrades
b. polar bears
c. cestodes
d. Pseudomys hermannsburgensis
e. camels
a. tardigrades
Single-celled Paramecium live in pond water (a hypotonic environment relative to the cytosol). They have a structural feature, a contractile vacuole, which enables them to osmoregulate. If sucrose or saline was added to the pond water in different concentrations (in millimolars, mM), under which conditions would you expect the contractile vacuole to be most active?
a. 0.0 mM sucrose
b. 0.05 mM saline
c. 1.0 mM saline
d. 0.08 mM sucrose
a. 0.0 mM sucrose
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. its kidney had ruptured
b. its cells dehydrated and lost the ability to metabolize
c. it was stressed and needed more time to acclimate to the new conditions
d. it was so hypertonic to the fresh water that it could not osmoregulate
d. it was so hypertonic to the fresh water that it could not osmoregulate
The body fluids of an osmoconformer would be ___ with its ___ environment.
a. hypoosmotic; seawater
b. hypoerosmotic; freshwater
c. isoosmotic; seawater
d. hyperosmotic; seawater
c. isoosmotic; seawater
An examination of a freshwater fish that died after being placed accidentally in saltwater would likely show that ___.
a. the gills became encrusted with salt, resulting in inadequate gas exchange and a resulting asphyxiation
b. loss of water by osmosis from cells in vital organs resulted in cell death and organ failure
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. high amounts of salt had diffused into the fish’s cells, causing them to swell and lyse
b. loss of water by osmosis from cells in vital organs resulted in cell death and organ failure
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
a. only I and II
b. only I and III
c. only II and III
d. I, II, and III
a. only I and II
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. a moist system of burrows, such as those of naked mole rats
c. lots of seawater, such as a bird living in a marine environment
d. a terrestrial environment, such as that supporting crickets
a. lots of fresh water flowing across the gills of a fish
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. Small, stagnant pools do not provide enough water to dilute the toxic ammonia.
b. Urea makes lungfish tissue in hypoosmotic to the pool.
c. The highly toxic urea makes the pool uninhabitable to potential competitors.
d. Urea takes less energy to synthesize than ammonia.
a. Small, stagnant pools do not provide enough water to dilute the toxic ammonia.
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?
a. Water would be forced out of the lumen of the Malpighian tubules through an osmotic gradient.
b. Water would be conserved, forming a hypertonic solution in the Malpighian.
c. The potassium gradient would have no effect on water movement.
d. There would be a net movement of water into the lumen of the tubules.
d. There would be a net movement of water into the lumen of the tubules.
Why are the renal artery and vein critical to the process of osmoregulation in vertebrates?
a. The renal artery and vein are the main pathways regulating how much is produced by the kidneys.
b. The kidneys require higher than normal levels of hormones.
c. The kidneys require constant and abnormally high oxygen supply to function.
d. The renal artery delivers blood with nitrogenous waste to the kidney and the renal vein brings blood with less nitrogenous wastes away from the kidneys.
d. The renal artery delivers blood with nitrogenous waste to the kidney and the renal vein brings blood with less nitrogenous wastes away from the kidneys.
