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AP Biology:  Membranes, Diffusion & Osmosis

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Multiple Choice

Identify the choice that best completes the statement or answers the question.
 
 
For the following questions, match the labeled component of the cell membrane in the figure below with its description.

nar001-1.jpg
 

 1. 

cholesterol
a.
A
b.
B
c.
C
d.
D
e.
E
 

 2. 

peripheral protein
a.
A
b.
B
c.
C
d.
D
e.
E
 

 3. 

fiber of the extracellular matrix
a.
A
b.
B
c.
C
d.
D
e.
E
 

 4. 

microfilament of the cytoskeleton
a.
A
b.
B
c.
C
d.
D
e.
E
 

 5. 

glycolipid
a.
A
b.
B
c.
C
d.
D
e.
E
 

 6. 

All of the following molecules are part of the cell membrane except
a.
lipids.
b.
nucleic acids.
c.
proteins.
d.
phosphate groups.
e.
steroids.
 

 7. 

Which of the following is correct about integral membrane proteins?
a.
They lack tertiary structure.
b.
They are loosely bound to the surface of the bilayer.
c.
They are usually transmembrane proteins.
d.
They are not mobile within the bilayer.
e.
They serve only a structural role in membranes.
 
 
Use the diagram of the U-tube in the figure below to answer the following questions.

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half filled with a solution of 2 M sucrose and 1 M glucose. Side B is half filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal.
nar002-1.jpg
 

 8. 

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. What will be the most probable result of this transfusion?
a.
It will have no unfavorable effect as long as the water is free of viruses and bacteria.
b.
The patient's red blood cells will shrivel up because the blood fluid is hypotonic compared to the cells.
c.
The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.
d.
The patient's red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells.
e.
The patient's red blood cells will burst because the blood fluid is hypertonic compared to the cells.
 

 9. 

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are
a.
hypotonic to both fresh water and the salt solution.
b.
hypertonic to both fresh water and the salt solution.
c.
hypertonic to fresh water but hypotonic to the salt solution.
d.
hypotonic to fresh water but hypertonic to the salt solution.
e.
isotonic with fresh water but hypotonic to the salt solution.
 

 10. 

Initially, in terms of tonicity, the solution in side A with respect to that in side B is
a.
hypotonic.
b.
plasmolyzed.
c.
isotonic.
d.
saturated.
e.
hypertonic.
 
 
Read the following information and refer to the figure below to answer the following questions.

Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.

nar003-1.jpg
 

 11. 

Which line represents the bag that contained a solution isotonic to the 0.6 molar solution at the beginning of the experiment?
a.
A
b.
B
c.
C
d.
D
e.
E
 

 12. 

Which line or lines represent(s) bags that contain a solution that is hypertonic at the end of 60 minutes?
a.
A and B
b.
B
c.
C
d.
D
e.
D and E
 

 13. 

The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is
a.
diffusion.
b.
active transport.
c.
osmosis.
d.
facilitated diffusion.
e.
exocytosis.
 

 14. 

Glucose 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. Using this information, which transport mechanism is most probably functioning in the intestinal cells?
a.
simple diffusion
b.
phagocytosis
c.
active transport pumps
d.
exocytosis
e.
facilitated diffusion
 

 15. 

The movement of potassium into an animal cell requires
a.
low cellular concentrations of sodium.
b.
high cellular concentrations of potassium.
c.
an energy source such as ATP or a proton gradient.
d.
a cotransport protein.
e.
a gradient of protons across the plasma membrane.
 

 16. 

Ions diffuse across membranes down their
a.
chemical gradients.
b.
concentration gradients.
c.
electrical gradients.
d.
electrochemical gradients.
e.
A and B are correct.
 

 17. 

All of the following processes take material into cells except
a.
pinocytosis.
b.
endocytosis.
c.
exocytosis.
d.
active transport.
e.
carrier-facilitated diffusion.
 

 18. 

White blood cells engulf bacteria through what process?
a.
exocytosis
b.
phagocytosis
c.
pinocytosis
d.
osmosis
e.
receptor-mediated exocytosis
 

 19. 

Which of the following types of molecules are the major structural components of the cell membrane?
a.
phospholipids and cellulose
b.
nucleic acids and proteins
c.
phospholipids and proteins
d.
proteins and cellulose
e.
glycoproteins and cholesterol
 

 20. 

When a membrane is freeze-fractured, the bilayer splits down the middle between the two layers of phospholipids. In an electron micrograph of a freeze-fractured membrane, the bumps seen on the fractured surface of the membrane are
a.
peripheral proteins.
b.
phospholipids.
c.
carbohydrates.
d.
integral proteins.
e.
cholesterol molecules.
 

 21. 

Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
a.
The double bonds form a kink in the fatty acid tail, forcing adjacent lipids to be further apart.
b.
Unsaturated fatty acids have a higher cholesterol content.
c.
Unsaturated fatty acids permit more water in the interior of the membrane.
d.
The double bonds block interaction among the hydrophilic head groups of the lipids.
e.
The double bonds result in a shorter fatty acid tail.
 

 22. 

What is one of the functions of cholesterol in animal cell membranes?
a.
facilitates transport of ions
b.
stores energy
c.
maintains membrane fluidity
d.
speeds diffusion
e.
phosphorylates ADP
 

 23. 

What kinds of molecules pass through a cell membrane most easily?
a.
large and hydrophobic
b.
small and hydrophobic
c.
large polar
d.
ionic
e.
monosaccharides such as glucose
 

 24. 

The selective permeability of biological membranes is dependent on which of the following?
a.
the type of transport proteins that are present in the membrane
b.
the lipid bilayer being permeable to primarily small, nonpolar molecules
c.
the types of carbohydrates on the surface of the membrane
d.
A and B only
e.
A, B, and C
 

 25. 

All of the following membrane activities require energy from ATP hydrolysis except
a.
facilitated diffusion.
b.
active transport.
c.
Na+ ions moving out of the cell.
d.
proton pumps.
e.
translocation of potassium into a cell.
 

 26. 

Which of the following characterizes the sodium-potassium pump?
a.
Sodium ions are pumped out of a cell against their gradient.
b.
Potassium ions are pumped into a cell against their gradient.
c.
The pump protein undergoes a conformational change.
d.
Only A and B are correct.
e.
A, B, and C are all correct.
 

 27. 

The difference between pinocytosis and receptor-mediated endocytosis is that
a.
pinocytosis brings only water into the cell, but receptor-mediated endocytosis brings in other molecules as well.
b.
pinocytosis increases the surface area of the plasma membrane whereas receptor-mediated endocytosis decreases the plasma membrane surface area.
c.
pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity.
d.
pinocytosis requires cellular energy, but receptor-mediated endocytosis does not.
e.
pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot.
 

 28. 

A pathogenic bacterium has been engulfed by a phagocytic cell as part of the nonspecific (innate) immune response. Which of the following illustrations best represents the response?
a.
mc028-1.jpg
c.
mc028-3.jpg
b.
mc028-2.jpg
d.
mc028-4.jpg
 

 29. 

mc029-1.jpg
Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data?
a.
At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia.
c.
The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration.
b.
The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
d.
In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.
 

 30. 

A representation of a cell membrane is shown in the diagram below.
mc030-1.jpg
How does the channel protein aid in the movement of particles through the cell membrane?
a.
It helps ions to bond and form larger compounds inside the cell.
c.
It enables ions to be removed from the cell against the concentration gradient.
b.
It causes ions inside the cell to attract water molecules from outside the cell.
d.
It allows ionic compounds to move freely through the membrane to reach equilibrium.
 

 31. 

A cell is placed in a solution with salt concentration much higher than the cell cytoplasm.  What will most likely happen to the cell?
a.
The cell will burst.
c.
The cell will shrink.
b.
The cell will swell.
d.
The cell will remain unchanged.
 

 32. 

Water is a solvent that forms solutions when mixed with solutes such as salt and sugar.  The table describes four cells and the surrounding liquid in which they are placed.
mc032-1.jpg
In which beaker will water move from the cell to the surrounding solution?
a.
beaker 1
c.
beaker 3
b.
beaker 2
d.
beaker 4
 

 33. 

Certain molecules are able to move across the cell membrane.  Which diagram shows the process of passive transport?
mc033-1.jpg
a.
image A
c.
image C
b.
image B
d.
image D
 

 34. 

The diagram shows dissolved sodium chloride (KCl) particles separated by a semi-permeable membrane.

mc034-1.jpg
After diffusion is complete, how will the contents of Side A and Side B compare?
a.
Side A will contain most of the K+ and Cl- particles
c.
Sides A and B will contain approximately equal amounts  of the K+ and Cl- particles
b.
Side B will contain most of the K+ and Cl- particles
d.
Side A will contain mostly  K+  particles, and Side B will contain mostly  Cl- particles.
 

 35. 

Materials move through the cell membranes by active and passive transport.  Which diagram illustrates active transport?
mc035-1.jpg
a.
Image A
c.
Image C
b.
Image B
d.
Image D
 

 36. 

What is a characteristic of active transport and not passive transport?
a.
energy use
c.
transport protein
b.
a cell membrane
d.
a concentration gradient
 

 37. 

What will most likely occur when a cell is placed into a saline solution that has a higher salt concentration than inside the cell?
a.
Water molecules will move into the cell.
c.
Salt molecules will move until the salt concentration is the same inside and outside of the cell.
b.
Salt molecules will move out of the cell.
d.
Water molecules will move until the salt concentration is the same inside and outside of the cell.
 

 38. 

Americans spend up to $100 billion annually  for bottled water (41 billion gallons).  The only beverages with higher sales are carbonated soft drinks.  Recent news stories have highlighted the fact that most bottled water comes from municipal water supplies (the same source as your tap water), although it may undergo an extra purification step called reverse osmosis.

Imagine two tanks that are separated by a membrane that is permeable to water but not to the dissolved minerals present in the water.  Tank A contains tap water and Tank B contains the purified water.  Under normal conditions, the purified water would cross the membrane to dilute the more concentrated tap water solution.  In the reverse osmosis process, pressure is applied to the tap water tank to force the water molecules across the membrane into the pure water tank.

After reverse osmosis system has been operating for 30 minutes, the solution in Tank A would
a.
be hypotonic to Tank B
c.
be hypertonic to Tank B
b.
be isotonic to Tank B
d.
move by passive transport to Tank B
 

 39. 

An ATP powered pump that transports a specific solute can indirectly drive the active transport of another solute in a mechanism called cotransport, as shown in the figure below.
mc039-1.jpg
The cotransporter protein is able to use the diffusion of H+ ions down their electrochemical gradient into the cell to drive the uptake of sucrose into the cell.  By what process are H+ ions being moved in this figure?
a.
active transport
c.
facilitated diffusion
b.
simple diffusion
d.
exocytosis
 

 40. 

White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs).  When looking at a sample of blood for WBCs , what could you do to reduce interference from RBCs?
a.
Mix the blood in a salty solution to cause the RBCs to lyse.
c.
Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.
b.
Mix the blood in an isotonic solution and allow the WBCs  to float to the top.
d.
Mix the blood in a hypertonic solution, which will cause the RBCs to lyse.
 



 
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