Chapters 44, 36

Multiple ChoiceIdentify the letter of the choice that best completes the statement or answers the question.

____ 1. Which of the following would be least likely to affect osmosis in plants?a. proton pumps in the membraneb. a difference in solute concentrationsc. receptor proteins in the membraned. aquaporinse. a difference in water potential

____ 2. Active transport involves all of the following except thea. slow movement through the lipid bilayer of a membrane.b. pumping of solutes across the membrane.c. hydrolysis of ATP.d. transport of solute against a concentration gradient.e. a specific transport protein in the membrane.

____ 3. Like many plant processes, transport of various materials in plants at the cellular level requires all of the following excepta. a proton gradient.b. ATP.c. specific membrane proteins.d. active transport.e. xylem membranes.

____ 4. Which of the following is not a function of the plasma membrane proton pump?a. hydrolyzes ATPb. produces a proton gradientc. generates a membrane potentiald. equalizes the charge on each side of a membranee. stores potential energy on one side of a membrane

____ 5. A unifying principle of cellular energetics that links energy-releasing processes to energy-consuming processes isa. active transport.b. chemiosmosis.c. ATP hydrolysis.d. water potential.e. source-sink relationships.

____ 6. Which of the following is an example of osmosis?a. flow of water out of a cellb. pumping of water into a cellc. flow of water between cellsd. both A and Be. both A and C

____ 7. The amount and direction of movement of water in plants can always be predicted by measuring which of the following?a. air pressureb. rainfallc. proton gradientsd. dissolved solutes

e. water potential ( )____ 8. Which of the following is true concerning the water potential of a plant cell?

a. It is higher than that of air.b. It is equal to zero when the cell is in pure water and is turgid.c. It is equal to 0.23 MPa.d. It becomes higher when K+ is actively moved into the cell.e. It becomes lower after the uptake of water by osmosis.

____ 9. Your laboratory partner has an open beaker of pure water. By definition, the water potential ( ) of this water isa. not meaningful, because it is an open beaker and not plant tissue.b. a negative number set by the volume of the beaker.c. a positive number set by the volume of the beaker.d. equal to the atmospheric pressure.e. zero.

____ 10. Which of the following has an effect on water potential ( ) in plants?a. air pressureb. water-attracting matricesc. dissolved solutesd. A and C onlye. A, B, and C

____ 11. If P = 0.3 MPa and S = -0.45 MPa, the resulting isa. +0.75 MPa.b. -0.75 MPa.c. -0.15 MPa.d. +0.15 MPa.e. impossible to calculate with this information.

____ 12. The value for in root tissue was found to be -0.15 MPa. If you take the root tissue and place it in a 0.1 M solution of sucrose ( = -0.23), net water flow woulda. be from the tissue into the sucrose solution.b. be from the sucrose solution into the tissue.c. be in both directions and the concentrations would remain equal.d. occur only as ATP was hydrolyzed in the tissue.e. be impossible to determine from the values given here.

____ 13. Compared to a cell with few aquaporins in its membrane, a cell containing many aquaporins willa. have a faster rate of osmosis.b. have a lower water potential.c. have a higher water potential.d. have a faster rate of active transport.e. be flaccid.

____ 14. Some botanists argue that the entire plant should be considered as a single unit rather than a composite of many individual cells. Which of the following cellular structures cannot be used to support this view?a. cell wallb. cell membranec. cytosold. tonoplaste. symplast

____ 15. Which of the following statements is false about bulk flow?a. It is driven primarily by pressure potential.b. It is more effective than diffusion over distances greater than 100 m.

c. It depends on a difference in pressure potential at the source and sink.d. It depends on the force of gravity on a column of water.e. It may be the result of either positive or negative pressure potential.

____ 16. Which of the following statements about xylem is incorrect?a. It conducts material upward.b. It conducts materials within dead cells.c. It transports mainly sugars and amino acids.d. It has a lower water potential than soil does.e. No energy input from the plant is required for xylem transport.

____ 17. Which of the following would likely not contribute to the surface area available for water absorption from the soil by a plant root system?a. root hairsb. endodermisc. mycorrhizaed. fungi associated with the rootse. fibrous arrangement of the roots

____ 18. Root hairs are most important to a plant because theya. anchor a plant in the soil.b. store starches.c. increase the surface area for absorption.d. provide a habitat for nitrogen-fixing bacteria.e. contain xylem tissue.

____ 19. What is the role of proton pumps in root hair cells?a. establish ATP gradientsb. acquire minerals from the soilc. pressurize xylem transportd. eliminate excess electronse. A and D only

____ 20. In plant roots, the Casparian strip is correctly described by which of the following?a. It is located in the walls between endodermal cells and cortex cells.b. It provides energy for the active transport of minerals into the stele from the cortex.c. It ensures that all minerals are absorbed from the soil in equal amounts.d. It ensures that all water and dissolved substances must pass through a cell before entering

the stele.e. It provides increased surface area for the absorption of mineral nutrients.

____ 21. All of the following describe an important component of the long-distance transport process in plants excepta. cohesion-tension-transpiration.b. osmosis.c. endodermis Casparian strip.d. active transport.e. bulk flow from source to sink.

____ 22. Pine seedlings grown in sterile potting soil grow much slower than seedlings grown in soil from the area where the seeds were collected. This is most likely becausea. the sterilization process kills the root hairs as they emerge from the seedling.b. the normal symbiotic fungi are not present in the sterilized soil.c. sterilization removes essential nutrients from the soil.d. water and mineral uptake is faster when mycorrhizae are present.e. both B and D

____ 23. A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. This living cell would be a part of which structure?a. the Casparian stripb. a guard cellc. the root epidermisd. the endodermise. the root cortex

____ 24. The following factors may sometimes play a role in the movement of sap through xylem. Which one depends on the direct expenditure of ATP by the plant?a. capillarity of water within the xylemb. evaporation of water from leavesc. cohesion among water moleculesd. concentration of ions in the symplaste. bulk flow of water in the root apoplast

____ 25. The soil solution is usually very dilute. After fertilizing a lawn, the concentration of salts in the soil builds up. What would be a response of grass roots to this increase?a. Water absorption would increase because of the higher solute potential in the soil.b. K+ will be actively transported into the root cells.c. Root cells will immediately dehydrate and die.d. Nutrient salts will diffuse into the root faster.e. There will be no noticeable effect.

____ 26. What is the main cause of guttation in plants?a. root pressureb. transpirationc. pressure flow in phloemd. plant injurye. condensation of atmospheric water

____ 27. One is most likely to see guttation in small plants when thea. transpiration rates are high.b. root pressure exceeds transpiration pull.c. preceding evening was hot, windy, and dry.d. water potential in the stele of the root is high.e. roots are not absorbing minerals from the soil.

____ 28. What is the main force by which most of the water within xylem vessels moves toward the top of a tree?a. active transport of ions into the steleb. atmospheric pressure on rootsc. evaporation of water through stomad. the force of root pressuree. osmosis in the root

____ 29. In which plant cell or tissue would the pressure component of water potential most often be negative?a. leaf mesophyll cellb. stem xylemc. stem phloemd. root cortex celle. root epidermis

____ 30. Water potential is generally most negative in which of the following parts of a plant?a. mesophyll cells of the leafb. xylem vessels in leavesc. xylem vessels in roots

d. cells of the root cortexe. root hairs

____ 31. Which of the following has the lowest (most negative) water potential?a. soilb. root xylemc. trunk xylemd. leaf cell wallse. leaf air spaces

____ 32. Which of the following is responsible for the cohesion of water molecules?a. hydrogen bonds between the oxygen atoms of a water molecule and cellulose in a vessel

cellb. covalent bonds between the hydrogen atoms of two adjacent water moleculesc. hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of

another water moleculed. covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of

another water moleculee. Cohesion has nothing to do with the bonding but is the result of the tight packing of the

water molecules in the xylem column.____ 33. Transpiration in plants requires all of the following except

a. adhesion of water molecules to cellulose.b. cohesion between water molecules.c. evaporation of water molecules.d. active transport through xylem cells.e. transport through tracheids.

____ 34. Which of the following statements about transport in plants is false?a. Weak bonding between water molecules and the walls of xylem vessels or tracheids helps

support the columns of water in the xylem.b. Hydrogen bonding between water molecules, which results in the high cohesion of the

water, is essential for the rise of water in tall trees.c. Although some angiosperm plants develop considerable root pressure, this is not sufficient

to raise water to the tops of tall trees.d. Most plant physiologists now agree that the pull from the top of the plant resulting from

transpiration is sufficient, when combined with the cohesion of water, to explain the rise of water in the xylem in even the tallest trees.

e. Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water in tall pine trees without transpiration pull.

____ 35. Active transport would be least important in the normal functioning of which of the following plant tissue types?a. leaf transfer cellsb. stem xylemc. root endodermisd. leaf mesophylle. root phloem

____ 36. Which of the following statements is false concerning the xylem?a. Xylem tracheids and vessels fulfill their vital function only after their death.b. The cell walls of the tracheids are greatly strengthened with cellulose fibrils forming

thickened rings or spirals.c. Water molecules are transpired from the cells of the leaves, and replaced by water

molecules in the xylem pulled up from the roots due to the cohesion of water molecules.

d. Movement of materials is by mass flow; materials move owing to a turgor pressure gradient from "source" to "sink."

e. In the morning, sap in the xylem begins to move first in the twigs of the upper portion of the tree, and later in the lower trunk.

____ 37. Xylem vessels, found in angiosperms, have a much greater internal diameter than tracheids, the only xylem conducting cells found in gymnosperms. The tallest living trees, redwoods, are gymnosperms. Which of the following is an advantage of tracheids over vessels for long-distance transport to great heights?a. Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders.b. The smaller the diameter of the xylem, the more likely cavitation will occur.c. Cohesive forces are greater in narrow tubes than in wide tubes of the same height.d. Only A and C are correct.e. A, B, and C are correct.

____ 38. Water rises in plants primarily by the cohesion-tension model. Which of the following is not true about this model?a. Water loss (transpiration) is the driving force for water movement.b. The "tension" of this model represents the excitability of the xylem cells.c. Cohesion represents the tendency for water molecules to stick together by hydrogen

bonds.d. The physical forces in the capillary-sized xylem cells make it easier to overcome gravity.e. The water potential of the air is more negative than the xylem.

____ 39. Assume that a particular chemical interferes with the establishment and maintenance of proton gradients across the membranes of plant cells. All of the following processes would be directly affected by this chemical excepta. photosynthesis.b. phloem loading.c. xylem transport.d. cellular respiration.e. stomatal opening.

____ 40. Guard cells do which of the following?a. protect the endodermisb. accumulate K+ and close the stomatac. contain chloroplasts that import K+ directly into the cellsd. guard against mineral loss through the stomatae. help balance the photosynthesis-transpiration compromise

____ 41. All of the following normally enter the plant through the roots excepta. carbon dioxide.b. nitrogen.c. potassium.d. water.e. calcium.

____ 42. Photosynthesis begins to decline when leaves wilt becausea. flaccid cells are incapable of photosynthesis.b. CO2 accumulates in the leaves and inhibits photosynthesis.c. there is insufficient water for photolysis during light reactions.d. stomata close, preventing CO2 entry into the leaf.e. the chlorophyll of flaccid cells cannot absorb light.

____ 43. The water lost during transpiration is an unfortunate side effect of the plant's exchange of gases. However, the plant derives some benefit from this water loss in the form ofa. evaporative cooling.

b. mineral transport.c. increased turgor.d. A and B onlye. A, B, and C

____ 44. Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree?a. cool, dry dayb. warm, dry dayc. warm, humid dayd. cool, humid daye. very hot, dry, windy day

____ 45. If the guard cells and surrounding epidermal cells in a plant are deficient in potassium ions, all of the following would occur excepta. photosynthesis would decrease.b. roots would take up less water.c. phloem transport rates would decrease.d. leaf temperatures would decrease.e. stomata would be closed.

____ 46. The opening of stomata is thought to involvea. an increase in the osmotic concentration of the guard cells.b. a decrease in the osmotic concentration of the stoma.c. active transport of water out of the guard cells.d. decreased turgor pressure in guard cells.e. movement of K+ from guard cells.

____ 47. Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant?a. subjecting the leaves of the plant to a partial vacuumb. increasing the level of carbon dioxide around the plantc. putting the plant in drier soild. decreasing the relative humidity around the plante. injecting potassium ions into the guard cells of the plant

____ 48. Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important becausea. chloroplasts sense when light is available so that guard cells will open.b. photosynthesis provides the energy necessary for contractile proteins to flex and open the

guard cells.c. guard cells will produce the O2 necessary to power active transport.d. ATP is required to power proton pumps in the guard cell membranes.e. both A and C

____ 49. All of the following are adaptations that help reduce water loss from a plant excepta. transpiration.b. sunken stomata.c. C4 photosynthesis.d. small, thick leaves.e. crassulacean acid metabolism.

____ 50. Which of the following best explains why CAM plants are not tall?a. They would be unable to move water and minerals to the top of the plant during the day.b. They would be unable to supply sufficient sucrose for active transport of minerals into the

roots during the day or night.

c. Transpiration occurs only at night, and this would cause a highly negative in the roots of a tall plant during the day.

d. Since the stomata are closed in the leaves, the Casparian strip is closed in the endodermis of the root.

e. With the stomata open at night, the transpiration rate would limit plant height.____ 51. As a biologist, it is your job to look for plants that have evolved structures with a selective advantage in dry,

hot conditions. Which of the following adaptations would be least likely to meet your objective?a. CAM plants that grow rapidlyb. small, thick leaves with stomata on the lower surfacec. a thick cuticle on fleshy leavesd. large, fleshy stems with the ability to carry out photosynthesise. plants that do not produce abscisic acid and have a short, thick tap root

____ 52. Phloem transport of sucrose can be described as going from "source to sink." Which of the following would not normally function as a sink?a. growing leafb. growing rootc. storage organ in summerd. mature leafe. shoot tip

____ 53. Which of the following is a correct statement about sugar movement in phloem?a. Diffusion can account for the observed rates of transport.b. Movement can occur both upward and downward in the plant.c. Sugar is translocated from sinks to sources.d. Only phloem cells with nuclei can perform sugar movement.e. Sugar transport does not require energy.

____ 54. Phloem transport is described as being from source to sink. Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports ____ from the ____ source to the ____ sink.a. amino acids; root; mycorrhizaeb. sugars; leaf; apical meristemc. nucleic acids; flower; rootd. proteins; root; leafe. sugars; stem; root

____ 55. Arrange the following five events in an order that explains the mass flow of materials in the phloem.

1. Water diffuses into the sieve tubes.2. Leaf cells produce sugar by photosynthesis.3. Solutes are actively transported into sieve tubes.4. Sugar is transported from cell to cell in the leaf.5. Sugar moves down the stem.

a. 2, 1, 4, 3, 5b. 1, 2, 3, 4, 5c. 2, 4, 3, 1, 5d. 4, 2, 1, 3, 5e. 2, 4, 1, 3, 5

____ 56. Water flows into the source end of a sieve tube becausea. sucrose has diffused into the sieve tube, making it hypertonic.b. sucrose has been actively transported into the sieve tube, making it hypertonic.c. water pressure outside the sieve tube forces in water.

d. the companion cell of a sieve tube actively pumps in water.e. sucrose has been dumped from the sieve tube by active transport.

____ 57. Which one of the following statements about transport of nutrients in phloem is false?a. Solute particles can be actively transported into phloem at the source.b. Companion cells control the rate and direction of movement of phloem sap.c. Differences in osmotic concentration at the source and sink cause a hydrostatic pressure

gradient to be formed.d. A sink is that part of the plant where a particular solute is consumed or stored.e. A sink may be located anywhere in the plant.

____ 58. According to the pressure flow hypothesis of phloem transport,a. solute moves from a high concentration in the "source" to a lower concentration in the

"sink."b. water is actively transported into the "source" region of the phloem to create the turgor

pressure needed.c. the combination of a high turgor pressure in the "source" and transpiration water loss from

the "sink" moves solutes through phloem conduits.d. the formation of starch from sugar in the "sink" increases the osmotic concentration.e. the pressure in the phloem of a root is normally greater than the pressure in the phloem of

a leaf.____ 59. As predicted by the pressure flow hypothesis of translocation in plants, phloem exudates from the severed

stylets of aphids near photosynthetic cells are sites ofa. relatively high hydrostatic pressure.b. relatively low hydrostatic pressure.c. relatively high concentrations of organic nutrients.d. active pumping of sucrose out of the sieve tube.e. A and C only

____ 60. Plants do not have a circulatory system like that of some animals. If a given water molecule did "circulate" (that is, go from one point in a plant to another and back), it would require the activity ofa. only the xylem.b. only the phloem.c. only the endodermis.d. both the xylem and the endodermis.e. both the xylem and the phloem.

____ 61. In the pressure flow hypothesis of translocation, what causes the pressure?a. root pressureb. the osmotic uptake of water by sieve tubes at the sourcec. the accumulation of minerals and water by the stele in the rootd. the osmotic uptake of water by the sieve tubes of the sinke. hydrostatic pressure in xylem vessels

____ 62. A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death?a. The sea star was stressed and needed more time to adapt to new conditions.b. The sea star is hypertonic to the freshwater, and it could not osmoregulate.c. The osmoregulatory system of the sea star could not handle the change in ionic content

presented by the freshwater.d. The contractile vacuoles used to regulate water content ruptured in the freshwater.e. The cells of the sea star dehydrated and lost the ability to metabolize.

____ 63. Organisms categorized as osmoconformers are most likelya. terrestrial.

b. marine.c. amphibious.d. found in freshwater streams.e. found in freshwater lakes.

____ 64. The body fluids of an osmoconformer would be ____ with its ____ environment.a. hypertonic; freshwaterb. isotonic; freshwaterc. hyperosmotic; saltwaterd. isoosmotic; saltwatere. hypoosmotic; saltwater

____ 65. Compared to the seawater around them, most marine invertebrates area. hyperosmotic.b. hypoosmotic.c. isoosmotic.d. hyperosmotic and isoosmotic.e. hypoosmotic and isoosmotic.

____ 66. Which feature of osmoregulation is found in both marine and freshwater bony fish?a. loss of water through the gillsb. gain of salt through the gillsc. loss of water in the urined. no drinking of watere. gain of water through food

____ 67. In addition to their role in gas exchange, fish gills are also directly involved ina. digestion.b. osmoregulation.c. thermoregulation.d. the excretion of uric acid.e. the release of atrial natriuretic proteins.

____ 68. All of the following represent adaptations by terrestrial animals to drying conditions excepta. anhydrobiosis.b. salt glands.c. efficient kidneys.d. impervious surfaces.e. increased thirst.

____ 69. The digestion and utilization of which nutrient creates the greatest need for osmoregulation by the kidneys?a. proteinb. starchc. fatd. oile. cellulose

____ 70. Which of the molecules shown in the figure below represents urea?

a. Ab. Bc. Cd. De. E

____ 71. Where and from what compound(s) is urea produced?a. liver from NH3 and CO2

b. liver from glycogenc. kidneys from glucosed. kidneys from glycerol and fatty acidse. bladder from uric acid and H2O

____ 72. Which of the following is true of urea? It isa. 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.

____ 73. Which of the following is true of ammonia?a. It is soluble in water.b. It can be stored as a precipitate.c. It has low toxicity relative to urea.d. Only A and C are true.e. A, B, and C are true.

____ 74. Which of the following is not a function of the liver?a. storage of glycogenb. secretion of ureac. production of plasma proteinsd. removal of glucose from the blood

e. detoxification of chemical poisons in the blood____ 75. The advantage of excreting 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.

____ 76. What is the main nitrogenous waste excreted by birds?a. ammoniab. nitratec. nitrited. ureae. uric acid

____ 77. Which of the following is a nitrogenous waste that requires hardly any water for its excretion?a. amino acidb. ureac. uric acidd. ammoniae. nitrogen gas

____ 78. What is the process called by which materials are returned to the blood from the nephron fluid?a. filtrationb. ultrafiltrationc. selective reabsorptiond. secretione. active transport

____ 79. Which organism(s) has excretory structures known as protonephridia?a. flatwormsb. earthwormsc. insectsd. vertebratese. both C and D

____ 80. Which organism(s) has excretory organs known as Malpighian tubules?a. earthwormsb. flatwormsc. insectsd. jellyfishe. both A and B

____ 81. Which of the following mechanisms for osmoregulation or nitrogen removal is incorrectly paired with its corresponding animal?a. metanephridium-earthwormb. Malpighian tubule-insectc. kidney-frogd. flame bulb-snakee. direct cellular exchange-marine invertebrate

____ 82. Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure?a. flame-bulb system of flatwormsb. protonephridia of rotifersc. metanephridia of earthworms

d. Malpighian tubules of insectse. kidneys of vertebrates

____ 83. What is the functional unit of the kidney?a. cortexb. vasa rectac. nephrond. bladdere. glomerulus

____ 84. The transfer of fluid from the glomerulus to Bowman's capsulea. results from active transport.b. transfers large molecules as easily as small ones.c. is very selective as to which small molecules are transferred.d. is mainly a consequence of blood pressure force-filtering the fluid.e. usually includes the transfer of red blood cells to the nephron tubule.

____ 85. Which part of the vertebrate nephron consists of capillaries?a. glomerulusb. loop of Henlec. distal tubuled. Bowman's capsulee. collecting duct

____ 86. Which of the following normally contains blood?a. vasa rectab. Bowman's capsulec. loop of Henled. proximal tubulee. collecting duct

Refer to the figure below, a diagram of a renal tubule, to answer the following questions.

____ 87. In which region would filtration occur?a. Ib. IIIc. IVd. Ve. VII

____ 88. In which region would urine become more concentrated?a. Ib. IIIc. IVd. Ve. VII

____ 89. In which region would nutrients be actively transported to the blood?a. Ib. IIc. IVd. Ve. VI

____ 90. Which part directly leads to the area where membranes become permeable to urea?a. IIIb. IVc. Vd. VIe. VII

____ 91. What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic?a. bicarbonateb. saltc. glucosed. ammoniae. HCl

____ 92. Which structure passes urine to the renal pelvis?a. loop of Henleb. collecting ductc. Bowman's capsuled. proximal tubulee. glomerulus

____ 93. Which structure possesses specialized cells called podocytes?a. loop of Henleb. collecting ductc. Bowman's capsuled. proximal tubulee. glomerulus

____ 94. Which structure is the first section of the nephron tubule into which the filtrate enters?a. loop of Henleb. collecting ductc. ureterd. proximal tubulee. glomerulus

____ 95. Which structure descends deep into the renal medulla only in juxtamedullary nephrons?a. loop of Henleb. collecting ductc. Bowman's capsuled. proximal convoluted tubulee. glomerulus

____ 96. All of the following are functions of the mammalian kidney excepta. water reabsorption.b. filtration of blood.c. excretion of nitrogenous waste.d. regulation of salt balance in the blood.e. production of urea as a waste product of protein catabolism.

____ 97. Which one of the following structures is found in birds and mammals but not in other vertebrates?a. juxtamedullary nephronsb. nephronsc. urethrad. uretere. Bowman's capsule

____ 98. Which of the following is not true concerning transport epithelia involved in water balance?a. One surface of the epithelium faces the outside environment directly or indirectly.b. The epithelium is a semipermeable barrier.c. The surface area is small, which prevents excessive water loss.d. The epithelium regulates the movement of solutes.e. Cells are joined by tight junctions.

____ 99. Which of the following processes of osmoregulation by the kidney is the least selective?a. salt pumping to control osmolarityb. H+ pumping to control pHc. reabsorptiond. filtratione. secretion

____ 100. Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected?a. No urine would be produced.b. A less-than-normal volume of hypoosmotic urine would be produced.c. A greater-than-normal volume of isoosmotic urine would be produced.d. A greater-than-normal volume of hyperosmotic urine would be produced.e. A less-than-normal volume of isoosmotic urine would be produced.

____ 101. Which one of the following is extremely important for water conservation in mammals?a. juxtamedullary nephronsb. Bowman's capsulec. urethrad. podocytese. ureter

____ 102. Which one of the following, if present in a urine sample, would likely be caused by trauma?a. amino acidsb. glucosec. saltsd. erythrocytese. vitamins

____ 103. A toxin that specifically blocks active transport in the loop of Henle might result in which of the following?a. a decrease in the interstitial concentration of NaClb. a decrease in the filtrate concentration ability of the kidneyc. an increase in the amount of interstitial urea to maintain interstitial osmolarityd. A and C only

e. A, B and C____ 104. Depending on salt intake and water availability, humans can produce urine that is

a. hyperosmotic to body fluids.b. hypoosmotic to body fluids.c. isoosmotic to body fluids.d. A and B are true.e. A, B, and C are true.

____ 105. Which structure increases the reabsorption of Na+ when stimulated by aldosterone?a. loop of Henleb. collecting ductc. Bowman's capsuled. proximal tubulee. distal tubules

____ 106. What would account for increased urine production as a result of drinking alcoholic beverages?a. increased aldosterone productionb. increased blood pressurec. decreased amount of antidiuretic hormone (ADH)d. increased reabsorption of water in the proximal tubulee. the osmoregulator cells of the brain increasing their activity

____ 107. In a laboratory experiment with three groups, one group of people 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. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least?a. beer the most, salt solution the leastb. salt solution the most, water the leastc. water the most, beer the leastd. beer the most, water the leaste. There will be no significant difference between these groups.

____ 108. Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system?a. sleepingb. spending several hours mowing the lawn on a hot dayc. eating a bag of potato chipsd. eating a pizza with olives and pepperonie. drinking several glasses of water

____ 109. Hormones involved in the production of urine include all of the following excepta. aldosterone.b. angiotensin.c. ADH.d. atrial natriuretic factor.e. secretin.

____ 110. Which statement is true about marine fishes?a. Compared to marine fishes, freshwater fishes have fewer glomeruli.b. The kidneys of marine fishes excrete little urine.c. Marine fishes lack proximal tubules.d. Marine fishes secrete uric acid to conserve water.e. Their kidneys produce filtrate at high rates.