Question 1

Oxygen diffuses into the capillaries of the lungs because there is

Accepted Answer

A)   a higher concentration of O2 in the alveoli than the capillaries.
B)   a higher concentration of O2 in the capillaries than the alveoli.
C)   a higher concentration of CO2 in the alveoli than the capillaries.
D)   a higher concentration of CO2 in the capillaries than the alveoli.
E)   an equal concentration of O2 in the alveoli and the capillaries.F) B) and E)
G) B) and D)

Question 2

A cell is placed in a solution of large carbohydrate molecules tagged with a red dye. Soon the cell is dark red, showing a concentration of the nutrient much higher than the external solution. We add a reagent that blocks the use of ATP. What result would you expect from this experiment?

Accepted Answer

A)   The nutrient would continue to rapidly enter the cell by diffusion because as a nutrient it is constantly being used in cell metabolism, so the cell will become more red.
B)   The color will remain the same since all future transfer will stop.
C)   The color will fade as the import of the nutrient stops and diffusion evens the concentrations as it moves the nutrient molecules out of the cell.
D)   The cell will continue to get darker since the import of the nutrient does not involve ATP.
E)   The cell will die without access to ATP.F) B) and E)
G) None of the above

Question 3

Which component of the extracellular matrix is responsible for forming proteoglycans?

Accepted Answer

A)   amino sugars
B)   fibronectin
C)   collagen
D)   elastin
E)   integrinF) A) and E)
G) A) and C)

Question 4

Radioactive isotopes are used to tag proteins in the cell membranes of mouse cells. These cells are then fused with human cells in cultures. What is the likely outcome of the tagged mouse proteins?

Accepted Answer

A)   The tagged proteins remain in the mouse cells and keep their position on the membrane.
B)   The tagged proteins remain in mouse cells but move anywhere across the mouse cell membrane.
C)   The tagged proteins drift across cell membranes and are soon found dispersed across both human and mouse cell membranes.
D)   None of the answer choices will occur since mouse cell membranes are unlike human cell membranes.
E)   None of the answer choices will occur since radioactive cells will soon die.F) A) and C)
G) B) and D)

Question 5

Macrophages, a type of white blood cells, are able to remove bacteria from our bloodstream and tissues by

Accepted Answer

A)   passive transport.
B)   facilitated diffusion.
C)   osmosis.
D)   pinocytosis.
E)   phagocytosis.F) A) and E)
G) B) and C)

Question 6

List the three types of intercellular junctions found in animal cells and indicate their function.

Accepted Answer

Adhesion junctions are the most common t...

Question 7

The plasma membrane is composed primarily of

Accepted Answer

A)   proteins and microtubules.
B)   lipids and actin filaments.
C)   lipids and microtubules.
D)   lipids and proteins.
E)   proteins and carbohydrates.F) None of the above
G) B) and C) D

Question 8

An isotonic solution means that the solute concentration outside the cell

Accepted Answer

A)   is greater than inside the cell.
B)   is less than inside the cell.
C)   is the same as inside the cell.
D)   has no effect on the cell.
E)   is greater than outside the cell.F) A) and E)
G) C) and E)

Question 9

A cell placed in a hypotonic solution will

Accepted Answer

A)   lose water.
B)   gain water.
C)   neither gain nor lose water.
D)   lose water initially and then gain water.
E)   gain water initially and then lose water.F) A) and C)
G) C) and D)

Question 10

Receptor-mediated endocytosis

Accepted Answer

A)   involves receptor proteins binding to specific molecules.
B)   protein pumps moving substances from low concentration to high concentration.
C)   protein pumps moving substances from high concentration to low concentration.
D)   the cell engulfing large particles.
E)   secretion of materials from a cell.F) B) and E)
G) A) and B)

Question 11

If we inspect most cell membranes in a living human body, we would find a nearly continuous flow of substances back and forth across the plasma membrane. Which of the following explains this continuous flow?

Accepted Answer

A)   Cell metabolism is constantly using up oxygen and raw materials; this lowers their concentration, so more will diffuse into the cell.
B)   Cell metabolism is constantly producing waste molecules; this increases their concentration, so more will diffuse into the cell.
C)   Cells produce useful secretions; this increases their concentration, and more will diffuse into the cell.
D)   Cell metabolism constantly produces oxygen in respiration; this increases the cell's affinity for carbon dioxide which diffuses into the cell.
E)   Cells are non-living and therefore anything can pass in and out of the cell.F) B) and D)
G) B) and C) A

Question 12

The number of mitochondria in a cell would be a general indicator of the extent of

Accepted Answer

A)   diffusion.
B)   facilitated transport.
C)   active transport.
D)   osmosis.
E)   both osmosis and diffusion.F) C) and D)
G) A) and B)

Question 13

Kidney dialysis relies on diffusion of various dissolved waste molecules (solutes)  across a non-living semipermeable membrane. If the concentration of solutes in the blood increases over time before dialysis is administered, what will happen to the rate of dialysis when it occurs?

Accepted Answer

A)   It will remain the same since there are no carrier molecules in a non-living membrane.
B)   The rate will slow down since the solute is more viscous.
C)   The rate will speed up since the concentration gradient is higher.
D)   It will remain the same since there is no active transport in a non-living membrane.
E)   The rate will depend on the amount of time given for diffusion to take place.F) B) and C)
G) B) and D)

Question 14

Which of the following factors could cause the cell membrane to become less permeable?

Accepted Answer

A)   if the channel proteins were to denature and become inactive
B)   if the molecules trying to enter the cell were decreased in size
C)   if the hydrophilic head of the phospholipids were to become hydrophobic while the hydrophobic tails become hydrophilic
D)   if the size of the protein channel was to increase
E)   All of the answer choices would cause the cell membrane to become less permeable.F) A) and D)
G) C) and D)

Question 15

Oxygen leaves the alveoli in the lungs and enters the capillaries by endocytosis.

Accepted Answer

A) True 
 B)False  False

Question 16

Which statement is true concerning movement of molecules across the cell membrane?

Accepted Answer

A)   Water and gas molecules cannot easily pass through the membrane.
B)   Small uncharged molecules do not pass through easily.
C)   Large molecules pass through easily.
D)   Charged molecules pass through easily.
E)   Lipid molecules pass through easily.F) B) and C)
G) A) and E)

Question 17

Active transport

Accepted Answer

A)   moves molecules or ions along their concentration gradient.
B)   involves carbohydrate pumps.
C)   is associated with large numbers of mitochondria.
D)   is associated with fat and skin cells.
E)   cannot be done by animal cells.F) C) and D)
G) A) and C)

Question 18

Once a solute and a solvent are evenly distributed in a solution, they will

Accepted Answer

A)   stop moving about.
B)   move back toward a concentration of the solvent.
C)   continue to move about but with no net gain in any direction.
D)   be out of equilibrium.
E)   move from a liquid to gaseous solution.F) A) and B)
G) A) and C)

Question 19

The same signaling molecule that binds to the receptor on the outside of the cell is used to alter gene expression in the nucleus.

Accepted Answer

A) True 
 B)False

Question 20

Which intercellular junction allows for the rapid movement of small molecules or ions to flow from one animal cell to the next?

Accepted Answer

A)   gap junctions
B)   tight junctions
C)   adhesion junctions
D)   desmosomes
E)   plasmodesmataF) B) and C)
G) C) and D)

Exam 4: Membrane Structure and Function

Oxygen diffuses into the capillaries of the lungs because there is

Correct AnswerverifiedShow Answer

A cell is placed in a solution of large carbohydrate molecules tagged with a red dye. Soon the cell is dark red, showing a concentration of the nutrient much higher than the external solution. We add a reagent that blocks the use of ATP. What result would you expect from this experiment?

Correct AnswerverifiedShow Answer

Which component of the extracellular matrix is responsible for forming proteoglycans?

Correct AnswerverifiedShow Answer

Radioactive isotopes are used to tag proteins in the cell membranes of mouse cells. These cells are then fused with human cells in cultures. What is the likely outcome of the tagged mouse proteins?

Correct AnswerverifiedShow Answer

Macrophages, a type of white blood cells, are able to remove bacteria from our bloodstream and tissues by

Correct AnswerverifiedShow Answer

List the three types of intercellular junctions found in animal cells and indicate their function.

Correct AnswerverifiedAdhesion junctions are the most common t...View AnswerShow Answer

The plasma membrane is composed primarily of

Correct AnswerverifiedD

An isotonic solution means that the solute concentration outside the cell

Correct AnswerverifiedShow Answer

A cell placed in a hypotonic solution will

Correct AnswerverifiedShow Answer

Receptor-mediated endocytosis

Correct AnswerverifiedShow Answer

If we inspect most cell membranes in a living human body, we would find a nearly continuous flow of substances back and forth across the plasma membrane. Which of the following explains this continuous flow?

Correct AnswerverifiedA

The number of mitochondria in a cell would be a general indicator of the extent of

Correct AnswerverifiedShow Answer

Kidney dialysis relies on diffusion of various dissolved waste molecules (solutes) across a non-living semipermeable membrane. If the concentration of solutes in the blood increases over time before dialysis is administered, what will happen to the rate of dialysis when it occurs?

Correct AnswerverifiedShow Answer

Which of the following factors could cause the cell membrane to become less permeable?

Correct AnswerverifiedShow Answer

Oxygen leaves the alveoli in the lungs and enters the capillaries by endocytosis.

Correct AnswerverifiedFalse

Which statement is true concerning movement of molecules across the cell membrane?

Correct AnswerverifiedShow Answer

Active transport

Correct AnswerverifiedShow Answer

Once a solute and a solvent are evenly distributed in a solution, they will

Correct AnswerverifiedShow Answer

The same signaling molecule that binds to the receptor on the outside of the cell is used to alter gene expression in the nucleus.

Correct AnswerverifiedShow Answer

Which intercellular junction allows for the rapid movement of small molecules or ions to flow from one animal cell to the next?

Correct AnswerverifiedShow Answer

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Adhesion junctions are the most common t...
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