Question 1

Cotransport systems directly provide energy for active transport of solutes. 
__________________

Accepted Answer

A) True 
 B)False  False

Question 2

Figure 5-1   Refer to the accompanying figure. Which best describes the red blood cells in Figure B?

Accepted Answer

A)  These red blood cells have been placed in an isotonic solution. 
B)  These red blood cells have swollen in response to a hypertonic external solution. 
C)  These red blood cells have swollen in response to a hypotonic external solution. 
D)  These red blood cells have shrunken in response to a hypertonic external solution. 
E)  These red blood cells have shrunken in response to a hypotonic external solution. 
A)  These red blood cells have been placed in an isotonic solution. 
B)  These red blood cells have swollen in response to a hypertonic external solution. 
C)  These red blood cells have swollen in response to a hypotonic external solution. 
D)  These red blood cells have shrunken in response to a hypertonic external solution. 
E)  These red blood cells have shrunken in response to a hypotonic external solution. D

Question 3

What type of molecule can rapidly cross a plasma membrane?

Accepted Answer

A)  large, polar molecules. 
B)  small, polar molecules. 
C)  large, hydrophilic molecules. 
D)  small, hydrophilic molecules. 
E)  small, hydrophobic molecules. 
A)  large, polar molecules. 
B)  small, polar molecules. 
C)  large, hydrophilic molecules. 
D)  small, hydrophilic molecules. 
E)  small, hydrophobic molecules. E

Question 4

The sodium-potassium pump is a carrier protein that maintains a(n) ____ gradient across the plasma membrane.

Accepted Answer

A)  polar 
B)  nonpolar 
C)  phosphorous 
D)  concentration 
E)  electrochemical 
A)  polar 
B)  nonpolar 
C)  phosphorous 
D)  concentration 
E)  electrochemical

Question 5

What is the passive movement of water along a concentration gradient?

Accepted Answer

A)  osmosis 
B)  cotransport 
C)  plasmolysis 
D)  simple diffusion 
E)  facilitated diffusion 
A)  osmosis 
B)  cotransport 
C)  plasmolysis 
D)  simple diffusion 
E)  facilitated diffusion

Question 6

What process halts the net movement of water from a hypotonic solution into a plant's cells and often provides the structural support to many plants?

Accepted Answer

A)  plasmolysis 
B)  turgur pressure 
C)  osmotic pressure 
D)  facilitated diffusion 
E)  dynamic equilibrium 
A)  plasmolysis 
B)  turgur pressure 
C)  osmotic pressure 
D)  facilitated diffusion 
E)  dynamic equilibrium

Question 7

A wilted flower placed in a vase of water for several hours became stiff and stood erect. When it was placed in a salt solution, it wilted. From this information, we can say that the cells of the flower are:

Accepted Answer

A)  hypotonic to both fresh water and the salt solution. 
B)  hypertonic to both the 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 to fresh water but hypotonic to the salt solution. 
A)  hypotonic to both fresh water and the salt solution. 
B)  hypertonic to both the 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 to fresh water but hypotonic to the salt solution.

Question 8

In the sodium-potassium pump, sodium ion release causes two K+ ions to be released into the cell. 
__________________

Accepted Answer

A) True 
 B)False

Question 9

Compare and contrast the mechanisms of the sodium-potassium pump and glucose-sodium cotransport systems.

Accepted Answer

Concepts to Consider: Role of

Question 10

Plasmolysis occurs in plant cells when the soil or water contains low concentration of salts or fertilizers. 
__________________

Accepted Answer

A) True 
 B)False

Question 11

Although glucose molecules constantly diffuse into a red blood cell along their concentration gradient, equilibrium is never reached and a steep concentration gradient is continually maintained. What causes this?

Accepted Answer

A)  The active transport of glucose 
B)  The very fast turnover rate of glucose metabolism 
C)  The ability of the cell to engulf glucose by pinocytosis 
D)  The continuous excretion of glucose from other parts of the cell 
E)  The rapid and continuous addition of phosphates onto the glucose molecules 
A)  The active transport of glucose 
B)  The very fast turnover rate of glucose metabolism 
C)  The ability of the cell to engulf glucose by pinocytosis 
D)  The continuous excretion of glucose from other parts of the cell 
E)  The rapid and continuous addition of phosphates onto the glucose molecules

Question 12

During phagocytosis, what may fuse with the vacuole to further degrade the ingested material?

Accepted Answer

A)  ligand 
B)  receptor 
C)  lysosome 
D)  phosphate 
E)  desmosome 
A)  ligand 
B)  receptor 
C)  lysosome 
D)  phosphate 
E)  desmosome

Question 13

Which statement about lipid bilayers is false ?

Accepted Answer

A)  They are inflexible. 
B)  They are self-sealing. 
C)  They resist forming free ends. 
D)  They can fuse with other bilayers. 
E)  They spontaneously form closed vesicles. 
A)  They are inflexible. 
B)  They are self-sealing. 
C)  They resist forming free ends. 
D)  They can fuse with other bilayers. 
E)  They spontaneously form closed vesicles.

Question 14

Once ligand molecules bind to receptors in coated pits of a plasma membrane, the next step of receptor-mediated endocytisis would be:

Accepted Answer

A)  coating detaches from vesicle 
B)  coated vesicle forms by endocytosis 
C)  ligands separate from receptors, which are recycled 
D)  contents of secondary lysosome are digested and released into the cytosol 
E)  endosome fuses with primary lysosome, forming secondary lysosome 
A)  coating detaches from vesicle 
B)  coated vesicle forms by endocytosis 
C)  ligands separate from receptors, which are recycled 
D)  contents of secondary lysosome are digested and released into the cytosol 
E)  endosome fuses with primary lysosome, forming secondary lysosome

Question 15

Compare and contrast the structure and functions of three of the following four intercellular junctions: desmosomes, gap junctions, tight junctions, and plasmodesmata.

Accepted Answer

Desmosomes consist of discs associated w

Question 16

Sketch and label a typical cell membrane. Provide a brief explanation for each of the labeled structures.

Accepted Answer

The answer of Sketch and label a typical cell membrane....

Question 17

In cell membranes cholesterol and glycoproteins are exposed to the extracellular surface for cell recognition and adhesion to other cells. 
__________________

Accepted Answer

A) True 
 B)False

Question 18

Figure 5-2   What cellular process is represented in the accompanying figure?

Accepted Answer

A)  lysis 
B)  exocytosis 
C)  cotransport 
D)  pinocytosis 
E)  facilitated diffusion 
A)  lysis 
B)  exocytosis 
C)  cotransport 
D)  pinocytosis 
E)  facilitated diffusion

Question 19

In cells that are constantly involved in secretion, an equivalent amount of membrane must be returned to the interior of the cell for each vesicle that fuses with the plasma membrane; if this does not occur, then what would happen?

Accepted Answer

A)  The cell surface would shrivel. 
B)  The cell surface will keep expanding. 
C)  The surface area would remain constant. 
D)  The number of membrane receptor proteins would decrease. 
E)  The ratio of cell surface would decrease, compared to cell volume. 
A)  The cell surface would shrivel. 
B)  The cell surface will keep expanding. 
C)  The surface area would remain constant. 
D)  The number of membrane receptor proteins would decrease. 
E)  The ratio of cell surface would decrease, compared to cell volume.

Question 20

Why can cholesterol act as a "fluidity buffer" in cell membranes?

Accepted Answer

A)  It is slightly amphipathic because of the presence of one hydroxyl group. 
B)  It is slightly hydrophobic because of the presence of one hydroxyl group. 
C)  It is slightly hydrophobic because of the presence of one carboxyl group. 
D)  It is slightly amphipathic because of the presence of one carboxyl group. 
E)  It is slightly hydrophilic because of the presence of one hydrocarbon group. 
A)  It is slightly amphipathic because of the presence of one hydroxyl group. 
B)  It is slightly hydrophobic because of the presence of one hydroxyl group. 
C)  It is slightly hydrophobic because of the presence of one carboxyl group. 
D)  It is slightly amphipathic because of the presence of one carboxyl group. 
E)  It is slightly hydrophilic because of the presence of one hydrocarbon group.

Exam 5: Biological Membranes

Cotransport systems directly provide energy for active transport of solutes. __________________

Figure 5-1 Refer to the accompanying figure. Which best describes the red blood cells in Figure B?

What type of molecule can rapidly cross a plasma membrane?

The sodium-potassium pump is a carrier protein that maintains a(n) ____ gradient across the plasma membrane.

What is the passive movement of water along a concentration gradient?

What process halts the net movement of water from a hypotonic solution into a plant's cells and often provides the structural support to many plants?

A wilted flower placed in a vase of water for several hours became stiff and stood erect. When it was placed in a salt solution, it wilted. From this information, we can say that the cells of the flower are:

In the sodium-potassium pump, sodium ion release causes two K+ ions to be released into the cell. __________________

Compare and contrast the mechanisms of the sodium-potassium pump and glucose-sodium cotransport systems.

Plasmolysis occurs in plant cells when the soil or water contains low concentration of salts or fertilizers. __________________

Although glucose molecules constantly diffuse into a red blood cell along their concentration gradient, equilibrium is never reached and a steep concentration gradient is continually maintained. What causes this?

During phagocytosis, what may fuse with the vacuole to further degrade the ingested material?

Which statement about lipid bilayers is false ?

Once ligand molecules bind to receptors in coated pits of a plasma membrane, the next step of receptor-mediated endocytisis would be:

Compare and contrast the structure and functions of three of the following four intercellular junctions: desmosomes, gap junctions, tight junctions, and plasmodesmata.

Sketch and label a typical cell membrane. Provide a brief explanation for each of the labeled structures.

In cell membranes cholesterol and glycoproteins are exposed to the extracellular surface for cell recognition and adhesion to other cells. __________________

Figure 5-2 What cellular process is represented in the accompanying figure?

In cells that are constantly involved in secretion, an equivalent amount of membrane must be returned to the interior of the cell for each vesicle that fuses with the plasma membrane; if this does not occur, then what would happen?

Why can cholesterol act as a "fluidity buffer" in cell membranes?

A View of Life

Atoms and Molecules the Chemical Basis of Life

The Chemistry of Life Organic Compounds

Organization of the Cell

Cell Communication

Energy and Metabolism

How Cells Make Atp Energy-Releasing Pathways

Photosynthesis Capturing Light Energy

Chromosomes, Mitosis, and Meiosis

The Basic Principles of Heredity

Dna the Carrier of Genetic Information

Gene Expression

Gene Regulation

Dna Technology and Genomics

Human Genetics and the Human Genome

Developmental Genetics

Introduction to Darwinian Evolution

Evolutionary Change in Populations

Speciation and Macroevolution

The Origin and Evolutionary History of Life

The Evolution of Primates

Understanding Diversity Systematics

Viruses and Subviral Agents

Bacteria and Archaea

Protists

Seedless Plants

Seed Plants

The Fungi

An Introduction to Animal Diversity

Sponges, Cnidarians, Ctenophores, and Protostomes

The Deuterostomes

Plant Structure Growth and Development

Leaf Structure and Function

Stem Structure and Transport

Roots and Mineral Nutrition

Reproduction in Flowering Plants

Plant Developmental Responses to External and Internal Signals

Animal Structure and Function an Introduction

Protection Support and Movement

Neural Signaling

Neural Regulation

Sensory Systems

Internal Transport

The Immune System Internal Defense

Gas Exchange

Processing Food and Nutrition

Osmoregulation and Disposal of Metabolic Wastes

Endocrine Regulation

Reproduction

Animal Development

Animal Behavior

Introduction to Ecology Population Ecology

Community Ecology

Ecosystems and the Biosphere

Ecology and the Geography of Life

Biological Diversity and Conservation Biology

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