Question 1

Which of the following membrane activities requires energy from ATP hydrolysis?

Accepted Answer

A)  facilitated diffusion of chloride ions across the membrane through a chloride channel 
B)  movement of Na⁺ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid 
C)  movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell 
D)  movement of carbon dioxide out of a paramecium 
A)  facilitated diffusion of chloride ions across the membrane through a chloride channel 
B)  movement of Na⁺ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid 
C)  movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell 
D)  movement of carbon dioxide out of a paramecium B

Question 2

Five dialysis bags, constructed of a type of membrane that is permeable to water and 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.
 
Which line in the graph represents the bag with the highest initial concentration of sucrose?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
A)  A 
B)  B 
C)  C 
D)  D A

Question 3

Five dialysis bags, constructed of a type of membrane that is permeable to water and 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.
 
Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic at 50 minutes?

Accepted Answer

A)  A and B 
B)  B 
C)  D 
D)  D and E 
A)  A and B 
B)  B 
C)  D 
D)  D and E B

Question 4

An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function?

Accepted Answer

A)  transporting ions against an electrochemical gradient 
B)  cell-cell recognition 
C)  attaching the plasma membrane to the cytoskeleton 
D)  establishing a diffusion barrier to charged molecules 
A)  transporting ions against an electrochemical gradient 
B)  cell-cell recognition 
C)  attaching the plasma membrane to the cytoskeleton 
D)  establishing a diffusion barrier to charged molecules

Question 5

Which of the following processes includes all of the others?

Accepted Answer

A)  osmosis 
B)  facilitated diffusion 
C)  passive transport 
D)  transport of an ion down its electrochemical gradient 
A)  osmosis 
B)  facilitated diffusion 
C)  passive transport 
D)  transport of an ion down its electrochemical gradient

Question 6

The sodium-potassium pump is called an electrogenic pump because it ________.

Accepted Answer

A)  pumps equal quantities of Na⁺ and K⁺ across the membrane in opposite directions 
B)  is used to drive the transport of glucose against a concentration gradient 
C)  decreases the voltage difference across the membrane 
D)  generates voltage across the membrane 
A)  pumps equal quantities of Na⁺ and K⁺ across the membrane in opposite directions 
B)  is used to drive the transport of glucose against a concentration gradient 
C)  decreases the voltage difference across the membrane 
D)  generates voltage across the membrane

Question 7

For the following questions, match the labeled component of the cell membrane in the figure with its description.
-  
Which component in the accompanying figure is a protein fiber of the extracellular matrix? 
A) A
B) B
C) C
D) E

Accepted Answer

The answer of For the following questions, match the labeled...

Question 8

When a cell is in equilibrium with its environment, which of the following processes occurs for substances that can diffuse through the plasma membrane?

Accepted Answer

A)  There is directed movement of substances into and out of the cell. 
B)  There is random movement of substances into and out of the cell. 
C)  There is no movement of substances into or out of the cell. 
D)  All movement of molecules across the plasma membrane occurs by active transport. 
A)  There is directed movement of substances into and out of the cell. 
B)  There is random movement of substances into and out of the cell. 
C)  There is no movement of substances into or out of the cell. 
D)  All movement of molecules across the plasma membrane occurs by active transport.

Question 9

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.
 
In the U-tube experiment illustrated above, which of the following statements correctly describes side B at equilibrium?

Accepted Answer

A)  The concentration of NaCl and glucose will decrease, and the water level will increase. 
B)  The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase. 
C)  The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will decrease. 
D)  The concentration of NaCl and glucose will increase, and the water level will decrease. 
A)  The concentration of NaCl and glucose will decrease, and the water level will increase. 
B)  The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase. 
C)  The concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will decrease. 
D)  The concentration of NaCl and glucose will increase, and the water level will decrease.

Question 10

The difference between pinocytosis and receptor-mediated endocytosis is that ________.

Accepted Answer

A)  pinocytosis brings only water molecules 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 can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot 
A)  pinocytosis brings only water molecules 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 can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot

Question 11

Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water ________.

Accepted Answer

A)  and the salt solution are both hypertonic to the cells of the celery stalks 
B)  is hypotonic and the salt solution is hypertonic to the cells of the celery stalks 
C)  is hypertonic and the salt solution is hypotonic to the cells of the celery stalks 
D)  is isotonic and the salt solution is hypertonic to the cells of the celery stalks 
A)  and the salt solution are both hypertonic to the cells of the celery stalks 
B)  is hypotonic and the salt solution is hypertonic to the cells of the celery stalks 
C)  is hypertonic and the salt solution is hypotonic to the cells of the celery stalks 
D)  is isotonic and the salt solution is hypertonic to the cells of the celery stalks

Question 12

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

Accepted Answer

A)  spread in a continuous layer over the inner and outer surfaces of the membrane. 
B)  confined to the hydrophobic interior of the membrane. 
C)  embedded in a lipid bilayer. 
D)  randomly oriented in the membrane, with no fixed inside-outside polarity. 
A)  spread in a continuous layer over the inner and outer surfaces of the membrane. 
B)  confined to the hydrophobic interior of the membrane. 
C)  embedded in a lipid bilayer. 
D)  randomly oriented in the membrane, with no fixed inside-outside polarity.

Question 13

For a protein to be an integral membrane protein, it would have to be ________.

Accepted Answer

A)  hydrophilic 
B)  hydrophobic 
C)  amphipathic, with at least one hydrophobic region 
D)  exposed on only one surface of the membrane 
A)  hydrophilic 
B)  hydrophobic 
C)  amphipathic, with at least one hydrophobic region 
D)  exposed on only one surface of the membrane

Question 14

Familial hypercholesterolemia is characterized by ________.

Accepted Answer

A)  defective LDL receptors on the cell membranes 
B)  poor attachment of the cholesterol to the extracellular matrix of cells 
C)  a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes 
D)  inhibition of the cholesterol active transport system in red blood cells 
A)  defective LDL receptors on the cell membranes 
B)  poor attachment of the cholesterol to the extracellular matrix of cells 
C)  a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes 
D)  inhibition of the cholesterol active transport system in red blood cells

Question 15

White blood cells engulf bacteria using ________.

Accepted Answer

A)  phagocytosis 
B)  pinocytosis 
C)  osmosis 
D)  receptor-mediated exocytosis 
A)  phagocytosis 
B)  pinocytosis 
C)  osmosis 
D)  receptor-mediated exocytosis

Question 16

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.
 
When the system illustrated above reaches equilibrium, the sugar concentrations on both sides of the U-tube will be ________.

Accepted Answer

A)  2 M sucrose, 1 M glucose 
B)  1 M sucrose, 2 M glucose 
C)  1 M sucrose, 1 M glucose 
D)  1.5 M sucrose, 1.5 M glucose 
A)  2 M sucrose, 1 M glucose 
B)  1 M sucrose, 2 M glucose 
C)  1 M sucrose, 1 M glucose 
D)  1.5 M sucrose, 1.5 M glucose

Question 17

Which of the following molecules dramatically increases the rate of diffusion of water across cell membranes?

Accepted Answer

A)  the sodium-potassium pump 
B)  aquaporins 
C)  gated ion channels 
D)  ATP 
A)  the sodium-potassium pump 
B)  aquaporins 
C)  gated ion channels 
D)  ATP

Question 18

According to the fluid mosaic model, a membrane ________.

Accepted Answer

A)  is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins 
B)  is composed of a single layer of fluid phospholipids between two layers of hydrophilic proteins 
C)  is composed of a mosaic of fluid polysaccharides and amphipathic proteins 
D)  is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins 
A)  is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins 
B)  is composed of a single layer of fluid phospholipids between two layers of hydrophilic proteins 
C)  is composed of a mosaic of fluid polysaccharides and amphipathic proteins 
D)  is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins

Question 19

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures?

Accepted Answer

A)  The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. 
B)  Unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly. 
C)  Unsaturated fatty acids are more nonpolar than saturated fatty acids. 
D)  The double bonds block interaction among the hydrophilic head groups of the lipids. 
A)  The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly. 
B)  Unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly. 
C)  Unsaturated fatty acids are more nonpolar than saturated fatty acids. 
D)  The double bonds block interaction among the hydrophilic head groups of the lipids.

Question 20

The voltage across a membrane is called the ________.

Accepted Answer

A)  chemical gradient 
B)  membrane potential 
C)  osmotic potential 
D)  electrochemical gradient 
A)  chemical gradient 
B)  membrane potential 
C)  osmotic potential 
D)  electrochemical gradient

Exam 7: Membrane Structure and Function

Which of the following membrane activities requires energy from ATP hydrolysis?

An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function?

Which of the following processes includes all of the others?

The sodium-potassium pump is called an electrogenic pump because it ________.

For the following questions, match the labeled component of the cell membrane in the figure with its description. - Which component in the accompanying figure is a protein fiber of the extracellular matrix? A) A B) B C) C D) E

When a cell is in equilibrium with its environment, which of the following processes occurs for substances that can diffuse through the plasma membrane?

The difference between pinocytosis and receptor-mediated endocytosis is that ________.

Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M salt solution become limp. From this we can deduce that the fresh water ________.

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

For a protein to be an integral membrane protein, it would have to be ________.

Familial hypercholesterolemia is characterized by ________.

White blood cells engulf bacteria using ________.

Which of the following molecules dramatically increases the rate of diffusion of water across cell membranes?

According to the fluid mosaic model, a membrane ________.

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures?

The voltage across a membrane is called the ________.

Evolution, the Themes of Biology, and Scientific Inquiry

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Vascular Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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