Biology Life on Earth 11th Edition by Audesirk - Test Bank

Biology Life on Earth 11th Edition by Audesirk – Test Bank

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Sample Questions Are Posted Below

Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The substances in cell membranes that form a barrier to the movement of materials across the
membrane are
A) nucleic acids.
B) external proteins.
C) carbohydrates.
D) internal proteins.
E) lipids.
1)
Answer: E
Chapter Section: 5.1
Learning Outcome: 5.1
2) The ________ portion of the cell membrane is responsible for the isolating function of the
membrane, whereas the ________ portion regulates exchange and communication with the
environment.
A) carbohydrate; lipid
B) lipid; protein
C) cholesterol; lipid
D) nucleic acid; lipid
E) protein; cholesterol
2)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.1
3) When a mouse cell and a human cell are fused, the membrane proteins of the two cells become
uniformly distributed over the surface of the hybrid cell. This occurs because
A) all proteins in the plasma membrane come from a membrane other than the human or the
mouse.
B) all proteins are anchored within the membrane.
C) proteins are asymmetrically distributed within the membrane.
D) many proteins can move around within the bilayer.
E) different membranes contain different proteins.
3)
Answer: D
Chapter Section: 5.1
Learning Outcome: 5.1
4) Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the
phospholipids point out and the tails point toward one another?
A) The tails are repelled by the aqueous environment, and the heads will directly interact with
the aqueous solution.
B) The tails are nonpolar and form hydrogen bonds with one another.
C) The heads are repelled by the water inside and outside the cell.
4)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.1
1
5) Plasma membranes are best described as a
A) double layer of phospholipids with hydrophobic tails facing toward one another.
B) single layer of phospholipids with water molecules attached along one side.
C) double layer of phospholipids with hydrophilic heads facing away from one another.
D) double layer of phospholipids with hydrophobic tails facing away from each other (toward
the cytoplasm of the cell and the extracellular solution).
E) single layer of phospholipids with tails pointed toward the inside of the cell.
5)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.1
6) The hydrophobic tails of a phospholipid bilayer are oriented toward the
A) both the extracellular fluid and cytoplasm.
B) interstitial fluid.
C) cytoplasm of the cell.
D) interior of the plasma membrane (i.e., toward one another).
E) extracellular fluid surrounding the cell.
6)
Answer: D
Chapter Section: 5.1
Learning Outcome: 5.1
7) Which of the following accounts for the fluid aspect of the fluid mosaic model of plasma
membranes?
A) One of the components of the membrane is water.
B) The bilayer permits diffusion of certain lipid-soluble substances.
C) The membrane is water soluble.
D) The plasma membrane is ʺfluidʺ because of the movement of substances across the
membrane.
E) The individual phospholipid molecules are not bonded to one another, so the movement of
certain proteins and lipids is possible within and through the bilayer.
7)
Answer: E
Chapter Section: 5.1
Learning Outcome: 5.1
8) According to the fluid mosaic model of cell membranes, which of the following is a TRUE
statement about membrane phospholipids?
A) They occur in an uninterrupted bilayer, with membrane proteins strictly anchored to the
surface of the membrane.
B) They have hydrophilic tails in the interior of the membrane.
C) They form a viscous fluid through which proteins shift and flow.
D) They are free to depart from the membrane and are dissolved in the surrounding solution.
E) They frequently flip-flop from one side of the membrane to the other.
8)
Answer: C
Chapter Section: 5.1
Learning Outcome: 5.1
2
9) In biological membranes, the phospholipids are arranged in a
A) single layer, with the phosphorus-containing region facing the interior of the cell.
B) bilayer, with the fatty acids pointing toward one another.
C) bilayer, with the fatty acids facing outward (facing the interior and exterior of the cell).
D) bilayer, with the phosphorus groups in the interior of the membrane.
E) single layer, with the fatty acids facing the interior of the cell.
9)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.1
10) The hydrophilic regions of a membrane protein are most likely to be found
A) only in muscle cell membranes.
B) exposed on the surface of the cell membrane.
C) attached to carbohydrates and facing the interior of a cell.
D) associated with the fatty acid region of the lipids.
E) in the interior of the membrane.
10)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.1
11) Suppose that plasma membranes were single layers of phospholipids rather than double layers,
and the heads faced the extracellular fluid. The interior of this hypothetical cell would have to be
A) hydrophobic and nonpolar.
B) hydrophobic only.
C) nonpolar only.
D) hydrophilic only.
E) polar only.
11)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.1
12) What would happen if the plasma membrane were composed solely of phospholipids and no
proteins?
A) Simple diffusion and osmosis would continue to occur.
B) The movement of molecules across the membrane would not be affected.
C) All movement of molecules across the membrane would cease.
D) Immune reactions would not be affected.
E) Only water would be able to pass through the membrane.
12)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.1
3
13) ISO membranes are inside-out membrane vesicles used by researchers in membrane studies. As a
molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following
order
A) head-tail-tail-head.
B) tail-head-tail-head.
C) head-tail-head-tail.
D) tail-head-head-tail.
E) head-head-tail-tail.
13)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.1
14) What structure in the membrane causes plasma membranes to resist freezing?
A) Cholesterol
B) Unsaturated fatty acid tails
C) Nonpolar heads of the phospholipids
D) Saturated fatty acid tails
E) Channel proteins
14)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.1
15) Within the fluid mosaic of a plasma membrane, what is the role of transport and channel proteins?
A) They are cell-surface connection sites.
B) They identify the cell.
C) They prevent the passage of amino acids.
D) They permit ions and water molecules to move through the plasma membrane.
E) They may set off cellular changes such as cell division or hormone secretion.
15)
Answer: D
Chapter Section: 5.1
Learning Outcome: 5.2
16) Recognition proteins are most important for
A) maintaining membrane integrity.
B) facilitated diffusion of molecules.
C) active transport of molecules.
D) distinguishing foreign cells from ʺselfʺ cells.
E) maintaining membrane fluidity.
16)
Answer: D
Chapter Section: 5.1
Learning Outcome: 5.1
4
17) In general, which of the following is (are) largely responsible for moving substances across the
plasma membrane, communicating with other cells, and identifying the cell?
A) Cytoskeleton
B) Proteins
C) Nucleic acids
D) Carbohydrates
E) Phospholipids
17)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.2
18) What prevents your immune system from attacking your own cells?
A) Receptor proteins
B) Fever
C) Cholesterol
D) Recognition proteins
E) Inadequate enzymes
18)
Answer: D
Chapter Section: 5.1
Learning Outcome: 5.1
19) The main lipids found in cell membranes are
A) glycerol.
B) phospholipids.
C) triglycerides.
D) waxes.
E) steroids.
19)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.1
20) Which of the following groups includes carrier and channel proteins?
A) Transport proteins B) Receptor proteins
C) Connection proteins D) Recognition proteins
20)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.2
21) Recognition proteins, such as those embedded on the surface of red blood cells, are composed of
A) glycoproteins. B) phospholipases.
C) steroids. D) nucleic acids.
21)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.1
5
22) Which of the following would NOT be found in a membrane?
A) Receptor protein
B) Cellulose
C) Cholesterol
D) Channel protein
E) Phospholipid
22)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.1
23) Cell membranes do all of the following EXCEPT
A) isolate the cellʹs contents from the external environment.
B) regulate the movement of substances between the cytoplasm of the cell and the extracellular
fluid.
C) provide attachments between cells.
D) allow communication between cells.
E) provide an energy source for the cell.
23)
Answer: E
Chapter Section: 5.1
Learning Outcome: 5.1
24) Which of the following types of membrane proteins are responsible for facilitated diffusion?
A) Connection proteins
B) Receptor proteins
C) Enzymes
D) Transport proteins
E) Recognition proteins
24)
Answer: D
Chapter Section: 5.1, 5.2
Learning Outcome: 5.2
25) Which of the following types of membrane proteins are responsible for maintaining cell shape by
linking the membrane protein with the cytoskeleton?
A) Enzymes
B) Receptor proteins
C) Recognition proteins
D) Connection proteins
E) Transport proteins
25)
Answer: D
Chapter Section: 5.1
Learning Outcome: 5.1
6
26) Which of the following types of membrane proteins are responsible for conveying external
messages such as those sent by a hormone signal?
A) Receptor proteins
B) Recognition proteins
C) Transport proteins
D) Enzymes
E) Connection proteins
26)
Answer: A
Chapter Section: 5.1
Learning Outcome: 5.1
27) The net movement of molecules from a high concentration to a low concentration is best described
by which of the following?
A) Passive transport
B) Osmosis
C) Endocytosis
D) Active transport
E) Exocytosis
27)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.2
28) For diffusion to occur, there must be
A) a gradient. B) ATP. C) water. D) a membrane.
28)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
29) The bacterium Vibrio cholerae releases a toxin that blocks a channel protein in the membranes of
cells that line the intestine. This toxin prevents the movement of sodium ions from the inside of the
intestine into cells. If the sodium ions could not move into the cells, how would this affect the
movement of water between the inside of the intestine and the cells?
A) Water would leave the intestines and enter the cells by osmosis.
B) Water would leave the intestines and enter the cells by facilitated diffusion.
C) Water would leave the cells and enter the intestines by facilitated diffusion.
D) The movement of water would not be affected.
E) Water would leave the cells and enter the intestines by osmosis.
29)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
30) Which of the following is an energy-requiring mode of transport that brings substances into a cell?
A) Simple diffusion B) Facilitated diffusion
C) Osmosis D) Active transport
30)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.2
7
31) In reference to diffusion, passive really means
A) no energy required.
B) no gradient.
C) in the air.
D) without a membrane.
E) very slowly.
31)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
32) Imagine that you fill a shallow tray with water and place a drop of red ink in one end of the tray
and a drop of green ink in the other end. Which of the following is TRUE at equilibrium?
A) The red and green ink do not mix at all.
B) The concentration of each ink is higher at one end of the tray than at the other end.
C) The red ink is uniformly distributed in one half of the tray, and the green ink is uniformly
distributed in the other half of the tray.
D) No predictions can be made without knowing the size of the ink molecules.
E) The red and green inks are both uniformly distributed throughout the tray.
32)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
33) Carbon dioxide crosses the plasma membrane by simple diffusion. The rate at which carbon
dioxide enters the cell is determined by the
A) amount of energy being produced by the cell.
B) concentration of carbon dioxide on each side of the membrane.
C) amount of oxygen being exported from the cell.
D) amount of transport protein in the membrane.
E) amount of carbon dioxide outside of the cell.
33)
Answer: B
Chapter Section: 5.2
Learning Outcome: 5.3
34) What is active transport?
A) Movement of molecules into or out of a cell using special proteins and not requiring an
expenditure of energy
B) Rapid movement of molecules in a solution
C) Movement of molecules into or out of a cell against a concentration gradient
D) Diffusion of molecules within a cell
E) Movement of molecules into or out of a cell down a concentration gradient
34)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.3
35) When substances move across a plasma membrane and down concentration gradients, this is
called
A) active transport. B) exocytosis.
C) passive transport. D) pinocytosis.
35)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.2
8
36) To say that a cell is ʺselectively permeableʺ means
A) sometimes water passes through, and sometimes it canʹt.
B) it is permeable to different substances than other cells.
C) only certain molecules can pass through.
D) it has different-sized perforations in the membrane.
E) permeability depends on gradient differences.
36)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.2
37) What happens when diffusion moves molecules across the plasma membrane?
A) Most molecules are capable of crossing the phospholipid bilayer at any location and at
basically the same rate.
B) Energy input is required to transport molecules.
C) The rate of diffusion cannot be influenced by the cell.
D) The cell gains needed materials and gets rid of excess materials very quickly.
E) The process is relatively slow and is driven by concentration gradients.
37)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
38) All of the following may influence the rate of simple diffusion across a selectively permeable
membrane EXCEPT the
A) concentration gradient.
B) lipid solubility of the molecule.
C) temperature.
D) size of the molecule.
E) size of the cell.
38)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
39) Molecules that permeate a plasma membrane by facilitated diffusion
A) require the aid of transport proteins.
B) move from an area of low concentration to an area of high concentration.
C) do so much more quickly than those crossing by simple diffusion.
D) require energy.
39)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.2
40) Which of the following occurs as an enzyme produced by a cell is secreted from the cell?
A) Pinocytosis
B) Receptor-mediated endocytosis
C) Endocytosis
D) Exocytosis
E) Phagocytosis
40)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.2
9
41) Molecules assisted by carrier proteins may cross a selectively permeable membrane by
A) simple diffusion.
B) osmosis.
C) facilitated diffusion.
D) endocytosis.
E) active transport.
41)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.2
42) The diffusion of water molecules across a selectively permeable membrane is called
A) hydrolysis.
B) osmosis.
C) facilitated diffusion.
D) exocytosis.
E) active transport.
42)
Answer: B
Chapter Section: 5.2
Learning Outcome: 5.3
43) If red blood cells are taken from the body and placed in a hypertonic solution, what happens to the
cells?
A) The cells remain unchanged due to equal water concentrations inside and outside the cells.
B) The cells swell and burst because water moves into them.
C) The cells shrivel up because water leaves them.
D) The cells remain unchanged due to equal solute concentrations inside and outside the cells.
E) They become white blood cells.
43)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.3
44) Imagine an artificial cell made with a selectively permeable membrane that allows water to pass
through but does not allow sugar to pass. If the artificial cell contains a 1% sugar solution and then
you place the cell in a 2% sugar solution, what happens?
A) Sugar diffuses in and water diffuses out until equilibrium is reached.
B) Water enters the cell because the solution is hypotonic to the cell.
C) There is no movement of water.
D) Water leaves the cell because the solution is hypertonic to the cell.
44)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.3
10
45) A freshwater protozoan, such as Paramecium, tends to ________ because it lives in a ________
environment.
A) gain water; isotonic
B) lose water; hypertonic
C) lose water; hypotonic
D) gain water; hypertonic
E) gain water; hypotonic
45)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
46) Solutions that cause water to enter cells by osmosis are called
A) permeable.
B) hypertonic.
C) hydrophilic.
D) isotonic.
E) hypotonic.
46)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
47) The blood plasma of a man who drinks salt water will become ________ to his red blood cells,
whereas the red blood cells will be ________ to the blood plasma.
A) hypotonic; hypertonic
B) hypertonic; isotonic
C) hypertonic; hypotonic
D) isotonic; hypertonic
E) isotonic; isotonic
47)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.3
48) The slowest rate of diffusion of dye particles in water will occur at
A) 20°C. B) 30°C. C) 60°C. D) 10°C.
48)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.3
49) Suppose you have two glucose solutions separated by a selectively permeable membrane. If there
is a concentration gradient of glucose across the membrane, then the solutions cannot be ________
relative to each other.
A) isotonic B) hypertonic C) hypotonic
49)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
11
50) Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This
means that
A) beaker A is hypertonic relative to beaker B.
B) beaker A is hypotonic relative to beaker B.
C) beaker A is isotonic relative to beaker B.
50)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
51) More than half a century ago, two cell biologists published details of their research involving
isolated membrane vesicles from chloroplasts. Normally, the fluid inside these vesicles is near
neutral. In an experiment, these membrane vesicles were soaked in an acidic solution (pH 4) until
the inside of the vesicle also became pH 4.
Based on the details provided in this scenario, by what mechanism could hydrogen ions have
crossed the vesicle membrane, and what do you think happened at the molecular level?
A) Simple diffusion; hydrogen ions moved into the vesicle through a channel protein.
B) Active transport; hydrogen ions moved out of the vesicle with the help of ATP energy.
C) Facilitated diffusion; hydrogen ions moved into the vesicle through a channel protein.
D) Pinocytosis; water moved from outside the vesicle to inside.
E) Osmosis; water moved from inside the vesicle to outside.
51)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.3
52) The secretion of excess water via a contractile vesicle of a Paramecium cell is an example of
A) facilitated diffusion.
B) active transport.
C) simple diffusion.
D) osmosis.
E) exocytosis.
52)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.3
53) Two aqueous solutions are separated by a selectively permeable membrane that allows water to
pass through but does not allow starch to pass through. Solution A is 10% starch and solution B is
5% starch. What will occur?
A) Water will diffuse from solution B to solution A.
B) Water will diffuse from solution A to solution B.
C) Starch will diffuse from solution B to solution A.
D) Starch will diffuse from solution A to solution B.
E) Both water and starch will diffuse from solution B to solution A.
53)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
12
54) The rate of facilitated diffusion of a molecule across a membrane will increase as the concentration
gradient of the molecule across the membrane increases to a certain point. Eventually, an increase
in the concentration of the molecule will not cause any further increase in facilitated diffusion.
Thus, there is a maximal rate of facilitated diffusion. This is because
A) there are a limited number of carrier proteins in the membrane.
B) facilitated diffusion requires ATP energy.
C) as the concentration gradient increases, molecules interfere with one another.
D) the diffusion constant depends on the concentration gradient.
E) the increased concentration gradient causes a situation far from equilibrium.
54)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
55) Osmosis moves water from a region of
A) high solute concentration to a region of low solute concentration.
B) negative osmotic potential to a region of positive osmotic potential.
C) low solute concentration of to a region of high solute concentration.
D) low concentration of water to a region of high concentration of water.
E) hypertonic solution to a region of hypotonic solution.
55)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.3
56) Glucose is a six-carbon sugar that diffuses slowly through artificial phospholipid bilayers. The
cells lining the small intestine, however, rapidly move large quantities of glucose from the
glucose-rich food into their glucose-poor cytoplasm. Given this information, which transport
mechanism is most probably functioning in the intestinal cells?
A) Exocytosis
B) Facilitated diffusion
C) Aquaporin transport
D) Simple diffusion
E) Osmosis
56)
Answer: B
Chapter Section: 5.2
Learning Outcome: 5.3
57) Two similar-sized animal cells are placed in a 0.5% sucrose solution. Cell A enlarges for a while
and then stops; cell B continues to enlarge and finally ruptures. Which of the following must have
been TRUE at the beginning of the experiment?
A) Cell A has a higher concentration of sucrose than cell B.
B) Cell A was hypertonic to the solution, and cell B was hypotonic.
C) Cell B has a higher concentration of sucrose than cell A.
D) Cell A was hypotonic to the solution, and cell B was hypertonic.
E) Cells A and B were isotonic to each other.
57)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.3
13
58) The cytoplasm of a certain cell, such as a neuron, already has a high concentration of K + ions. How
can K+ ions continue to enter the cell?
A) Infusion
B) Active transport
C) Exocytosis
D) Osmosis
E) Facilitated diffusion
58)
Answer: B
Chapter Section: 5.2
Learning Outcome: 5.2
59) The gases O2 and CO2 enter or leave a plant cell by
A) facilitated diffusion.
B) osmosis.
C) facilitated transport.
D) simple diffusion.
E) active transport.
59)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.3
60) Active transport requires all of the following EXCEPT
A) a gradient.
B) transport proteins.
C) ATP.
D) a membrane.
E) aquaporins.
60)
Answer: E
Chapter Section: 5.2
Learning Outcome: 5.2
61) The process in which white blood cells engulf bacteria is termed
A) exocytosis.
B) reception.
C) pinocytosis.
D) phagocytosis.
E) recognition.
61)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.2
62) Which process accounts for the movement of solid particles (such as food) into some animal cells?
A) Active transport
B) Simple diffusion
C) Facilitated diffusion
D) Phagocytosis
E) Osmosis
62)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.2
14
63) Cells use exocytosis to
A) move away from danger.
B) ingest nutrients.
C) pump hydrogen molecules across the membrane.
D) release substances from the cell.
E) create new cells.
63)
Answer: D
Chapter Section: 5.2
Learning Outcome: 5.2
64) If you forget to water your favorite plant, all of the following will occur at a cellular level EXCEPT
A) turgor pressure will build up in the cell.
B) water will move out of the vacuoles by osmosis.
C) water will move out of the cytosol by osmosis.
D) the plasma membrane will shrink away from the cell wall.
E) osmosis will occur.
64)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.2
65) If a frog egg cell is placed into a hypotonic solution, it will
A) swell via osmosis.
B) shrivel via active transport.
C) shrivel via facilitated diffusion.
D) shrivel via osmosis.
E) swell via facilitated diffusion.
65)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.3
66) Which of the following requires adenosine triphosphate?
A) Active transport B) Simple diffusion
C) Facilitated diffusion D) Osmosis
66)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.2
67) Specialized cell junctions include all of the following EXCEPT
A) gap junctions. B) desmosomes.
C) phospholipases. D) tight junctions.
67)
Answer: C
Chapter Section: 5.3
Learning Outcome: 5.4
15
68) The electrical signal for a muscle to contract passes rapidly from one cell to the next via
A) internal proteins.
B) gap junctions.
C) plasmodesmata.
D) desmosomes.
E) tight junctions.
68)
Answer: B
Chapter Section: 5.3
Learning Outcome: 5.4
69) Adhesion of cells within animal tissues is accomplished by cell-to-cell junctions called
A) desmosomes. B) tight junctions.
C) gap junctions. D) plasmodesmata.
69)
Answer: A
Chapter Section: 5.3
Learning Outcome: 5.4
70) The urinary bladder is protected from leaking by cell-to-cell junctions called
A) desmosomes. B) tight junctions.
C) gap junctions. D) plasmodesmata.
70)
Answer: B
Chapter Section: 5.3
Learning Outcome: 5.4
71) Protein channels that provide passage for hormones and nutrients between animal cells are termed
A) desmosomes. B) tight junctions.
C) gap junctions. D) plasmodesmata.
71)
Answer: C
Chapter Section: 5.3
Learning Outcome: 5.4
72) You observe a cell under a microscope and you can clearly see a cell wall, a vacuole, and
cytoplasmic connections. These cytoplasmic connections must be
A) plasmodesmata.
B) osmotic channels.
C) tight junctions.
D) gap junctions.
E) desmosomes.
72)
Answer: A
Chapter Section: 5.3
Learning Outcome: 5.4
TRUE/FALSE. Write ʹTʹ if the statement is true and ʹFʹ if the statement is false.
73) Carrier molecules in the plasma membrane are required only for active transport. 73)
Answer: True False
Chapter Section: 5.2
Learning Outcome: 5.1
16
74) Osmosis is the diffusion of water molecules across selectively permeable membranes. 74)
Answer: True False
Chapter Section: 5.2
Learning Outcome: 5.3
75) After a dye diffuses uniformly throughout a glass of water, the dye molecules are no longer
moving.
75)
Answer: True False
Chapter Section: 5.2
Learning Outcome: 5.3
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
76) The most common lipids in biological membranes are ________. 76)
Answer: phospholipids
Chapter Section: 5.1
Learning Outcome: 5.1
77) Phospholipids contain two different parts: a ________ head and a pair of ________ tails. 77)
Answer: polar and/or hydrophilic; nonpolar and/or hydrophobic
Chapter Section: 5.1
Learning Outcome: 5.1
78) The movement of molecules across a cell membrane via a transport protein in which no
energy is required is called ________ diffusion, and the movement of molecules across a
cell membrane via a protein in which energy (i.e., ATP) is required is called ________
transport.
78)
Answer: facilitated; active
Chapter Section: 5.2
Learning Outcome: 5.2
79) Facilitated diffusion and active transport both require ________ for the movement of
molecules across the membrane.
79)
Answer: transport proteins
Chapter Section: 5.2
Learning Outcome: 5.2
80) ________ is used by white blood cells to consume large particles such as bacteria. 80)
Answer: Phagocytosis
Chapter Section: 5.2
Learning Outcome: 5.2
81) Communication between cells occurs via ________ in plant cells and via ________ in
animal cells.
81)
Answer: plasmodesmata; gap junctions
Chapter Section: 5.3
Learning Outcome: 5.4
17
82) The cells of the bladder are joined to one another by ________ that prevent substances
from passing between the cells of this tissue.
82)
Answer: tight junctions
Chapter Section: 5.3
Learning Outcome: 5.4
83) The antibiotic polymyxin B attaches itself to the phospholipids in the phospholipid bilayer
and increases the permeability of the membrane. Describe what will occur as a result.
83)
Answer: The plasma membrane will lose its ability to be a selectively permeable barrier.
Substances will leak out of the cell, and some previously excluded substances may
enter. Eventually, the cell will die.
Chapter Section: 5.1
Learning Outcome: 5.1
84) How does the cell membrane act as a ʺgatekeeperʺ for the cell? 84)
Answer: It separates the internal and external cell environments, it regulates the exchange of
substances between the external environment and the cytoplasm, and it allows for
communication between cells.
Chapter Section: 5.1
Learning Outcome: 5.1
85) Compare and contrast facilitated diffusion and active transport. 85)
Answer: Both require membrane transport proteins. However, facilitated diffusion does not
require energy and moves substances down a concentration gradient. Active
transport requires energy and moves substances against a concentration gradient.
Chapter Section: 5.2
Learning Outcome: 5.2
86) Compare and contrast osmosis and simple diffusion. 86)
Answer: Both are passive processes. However, osmosis refers to the movement of water
down its concentration gradient across a selectively permeable membrane. No
membrane or membrane protein is required for simple diffusion.
Chapter Section: 5.2
Learning Outcome: 5.3
87) Why is the biological membrane said to be selectively permeable? 87)
Answer: It allows only some molecules to pass through while barring others.
Chapter Section: 5.2
Learning Outcome: 5.1
88) Suppose a bag made of a selectively permeable membrane was filled with a 5% solution of
glucose and sealed. What would happen if the bag was placed in pure water or in a 10%
glucose solution?
88)
Answer: In pure water, the bag would swell as water moves in. In the glucose solution, the
bag would shrink as water moves out.
Chapter Section: 5.2
Learning Outcome: 5.3
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89) Why does the cell perform endocytosis in addition to active and passive transport? 89)
Answer: Endocytosis is required for the transport of proteins, microbes, extracellular fluid,
and specific molecules that are all larger than the molecule size transported by
active and passive transport.
Chapter Section: 5.2
Learning Outcome: 5.2
90) Distinguish among the three types of endocytosis: pinocytosis, receptor-mediated
endocytosis, and phagocytosis.
90)
Answer: Pinocytosis is for fluid intake, receptor-mediated endocytosis is for the uptake of
specific molecules, and phagocytosis is used to move large particles into the cell.
Chapter Section: 5.2
Learning Outcome: 5.2
91) Both plant cells and animal cells will swell if placed in a hypotonic solution. However,
only the animal cell will burst. Why?
91)
Answer: Water will enter both cells due to osmosis. In the animal cell, water will continue to
enter as long as the extracellular solution is hypotonic, causing the pliable animal
cell membrane to eventually break and the cell to burst. The stiff cell wall found in
plant cells but not animal cells will not expand indefinitely. At some point, as the
cytoplasm of the plant cell expands, the cell wall will exert a back pressure on the
cell. Further water uptake will be prevented and the plant cell will not burst.
Chapter Section: 5.2
Learning Outcome: 5.1
92) When very small viruses infect a plant cell by crossing its membrane, the viruses often
spread rapidly throughout the entire plant without crossing additional membranes.
Explain how this occurs.
92)
Answer: The viruses travel cell to cell via the plasmodesmata junctions.
Chapter Section: 5.3
Learning Outcome: 5.4
93) Compare and contrast the intercellular junctions that allow communication between plant
and animal cells.
93)
Answer: Gap junctions in animal cells and plasmodesmata in plant cells are both involved in
coordinating the actions of adjacent cells.
Chapter Section: 5.3
Learning Outcome: 5.4
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MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
94) Based on these four illustrations of diffusion, which mode would most likely be used to transport
oxidized zinc (which has a charge of +2) through the cell membrane?
A) Osmosis through aquaporins
B) Simple diffusion through the bilayer
C) Facilitated diffusion through channel proteins
D) Facilitated diffusion through carrier proteins
94)
Answer: C
Chapter Section: 5.2
Learning Outcome: 5.2
95) If the radius of one cell were twice as large as the radius of another cell, how much higher or lower
would its surface-area-to-volume ratio be?
A) 1/2 lower B) 2 times lower C) 10 times higher D) 2 times higher
95)
Answer: A
Chapter Section: 5.2
Learning Outcome: 5.1
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96) Cystic fibrosis is a genetic disease that leads to the production of excessive, thick mucus in the
respiratory tract, causing frequent and serious respiratory infections. The defect is due to the
production of a faulty membrane protein for the transport of the chloride ion. The protein exists in
membranes, but it doesnʹt function normally.
Based on this scenario, what is occurring at the molecular level in a person with cystic fibrosis?
A) A receptor protein is being adversely affected.
B) A channel protein is being adversely affected.
C) Protein filaments in the cytoplasm are being adversely affected.
D) A recognition protein is being adversely affected.
E) A carrier protein is being adversely affected.
96)
Answer: B
Chapter Section: 5.1
Learning Outcome: 5.2
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