Question 1

What is the voltage across a membrane called?

Accepted Answer

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

Question 2

Submerging a red blood cell in distilled water will result in

Accepted Answer

A)  plasmolysis of the cell. 
B)  lysis of the cell. 
C)  the cell becoming turgid. 
D)  the cell becoming flacid. 
A)  plasmolysis of the cell. 
B)  lysis of the cell. 
C)  the cell becoming turgid. 
D)  the cell becoming flacid. B

Question 3

The cell membranes of Antarctic ice fish might have which of the following adaptations?

Accepted Answer

A)  a high percentage of very long chain saturated fatty acids 
B)  no cholesterol 
C)  a high percentage of unsaturated fatty acids 
D)  a high percentage of trans fatty acids 
A)  a high percentage of very long chain saturated fatty acids 
B)  no cholesterol 
C)  a high percentage of unsaturated fatty acids 
D)  a high percentage of trans fatty acids C

Question 4

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Accepted Answer

A)  It is a peripheral membrane protein. 
B)  It exhibits a specificity for a particular type of molecule. 
C)  It requires the expenditure of cellular energy to function. 
D)  It works against a concentration gradient. 
A)  It is a peripheral membrane protein. 
B)  It exhibits a specificity for a particular type of molecule. 
C)  It requires the expenditure of cellular energy to function. 
D)  It works against a concentration gradient.

Question 5

Figure 5.1
For the following questions, match the labeled component of the cell membrane in Figure 5.1 with its description.
-Which component in the figure is a fiber of the extracellular matrix?

Accepted Answer

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

Question 6

Celery stalks that are immersed in fresh water for several hours become turgid (stiff). Celery stalks left in a 0.15 M salt solution become flaccid (limp). From this we can deduce that

Accepted Answer

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

Question 7

When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that

Accepted Answer

A)  the integral membrane proteins are not strong enough to hold the bilayer together. 
B)  water that is present in the middle of the bilayer freezes and is easily fractured. 
C)  the hydrophobic interactions between the fatty acid tails of the two phospholipid monolayers are the weakest interactions in the membrane. 
D)  the carbon-carbon bonds of the phospholipid tails are easily broken. 
A)  the integral membrane proteins are not strong enough to hold the bilayer together. 
B)  water that is present in the middle of the bilayer freezes and is easily fractured. 
C)  the hydrophobic interactions between the fatty acid tails of the two phospholipid monolayers are the weakest interactions in the membrane. 
D)  the carbon-carbon bonds of the phospholipid tails are easily broken.

Question 8

In what way do the membranes of a eukaryotic cell vary?

Accepted Answer

A)  Phospholipids are found only in certain membranes. 
B)  Certain proteins are unique to each kind of membrane. 
C)  Only certain membranes of the cell are selectively permeable. 
D)  Only certain membranes are constructed from amphipathic molecules. 
A)  Phospholipids are found only in certain membranes. 
B)  Certain proteins are unique to each kind of membrane. 
C)  Only certain membranes of the cell are selectively permeable. 
D)  Only certain membranes are constructed from amphipathic molecules.

Question 9

The primary function of G proteins in signal transduction is

Accepted Answer

A)  transducing the signal from an activated receptor to the next protein in the pathway. 
B)  binding extracellular signal molecules to activate the pathway. 
C)  converting ATP to cATP to amplify the signal. 
D)  phosphorylating relay molecules in the pathway. 
A)  transducing the signal from an activated receptor to the next protein in the pathway. 
B)  binding extracellular signal molecules to activate the pathway. 
C)  converting ATP to cATP to amplify the signal. 
D)  phosphorylating relay molecules in the pathway.

Question 10

The sodium-potassium pump generates the following concentration gradients across the plasma membrane:

Accepted Answer

A)  high [Na+] and [K+] inside the cell and low [Na+] and [K+] outside. 
B)  low [Na+] and [K+] inside the cell and high [Na+] and [K+] outside. 
C)  low [Na+] and high [K+] inside the cell and high [Na+] and low [K+] outside. 
D)  high [Na+] and low [K+] inside the cell and low [Na+] and high [K+] outside. 
A)  high [Na+] and [K+] inside the cell and low [Na+] and [K+] outside. 
B)  low [Na+] and [K+] inside the cell and high [Na+] and [K+] outside. 
C)  low [Na+] and high [K+] inside the cell and high [Na+] and low [K+] outside. 
D)  high [Na+] and low [K+] inside the cell and low [Na+] and high [K+] outside.

Question 11

The mechanism by which testosterone alters cell function is by

Accepted Answer

A)  binding to a receptor protein that enters the nucleus and activates specific genes. 
B)  serving as a transmembrane signal receptor that activates cell-signaling pathways. 
C)  acting as a steroid signal receptor that activates ion channel proteins. 
D)  serving as a second messenger that activates cell-signaling pathways. 
A)  binding to a receptor protein that enters the nucleus and activates specific genes. 
B)  serving as a transmembrane signal receptor that activates cell-signaling pathways. 
C)  acting as a steroid signal receptor that activates ion channel proteins. 
D)  serving as a second messenger that activates cell-signaling pathways.

Question 12

What kinds of molecules pass through a cell membrane most easily?

Accepted Answer

A)  large hydrophobic 
B)  small hydrophobic 
C)  large polar 
D)  small ionic 
E)  large and hydrophilic 
A)  large hydrophobic 
B)  small hydrophobic 
C)  large polar 
D)  small ionic 
E)  large and hydrophilic

Question 13

Which of the following statements correctly describes the normal tonicity relationships between typical plant and animal cells and their respective environments?

Accepted Answer

A)  Animal cells are generally in a hypotonic solution, and plant cells are generally in an isotonic solution. 
B)  Animal cells are generally in an isotonic solution, and plant cells are generally in a hypotonic solution. 
C)  Animal cells are generally in an isotonic solution, and plant cells are generally in a hypertonic solution. 
D)  Animal cell are generally in a hypertonic solution, and plant cells are generally in an isotonic solution. 
E)  Animal cells are generally in a hypertonic solution, the plant cells are generally in a hypotonic solution. 
A)  Animal cells are generally in a hypotonic solution, and plant cells are generally in an isotonic solution. 
B)  Animal cells are generally in an isotonic solution, and plant cells are generally in a hypotonic solution. 
C)  Animal cells are generally in an isotonic solution, and plant cells are generally in a hypertonic solution. 
D)  Animal cell are generally in a hypertonic solution, and plant cells are generally in an isotonic solution. 
E)  Animal cells are generally in a hypertonic solution, the plant cells are generally in a hypotonic solution.

Question 14

Figure 5.2
The solutions in the two arms of this U-tube (Figure 5.2) 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 are equal. Refer to the figure to answer the following question(s).
-After the system depicted in the figure reaches equilibrium, what changes are observed with respect to the concentrations of sugars?

Accepted Answer

A)  The concentration of sucrose is equal in sides A and B and the concentrations of glucose are unchanged. 
B)  The concentrations of glucose and sucrose are equal in sides A and B. 
C)  The concentration of glucose is equal in sides A and B and the concentrations of sucrose are unchanged. 
D)  The water levels change, but the concentrations of glucose and sucrose in sides A and B are unchanged. 
A)  The concentration of sucrose is equal in sides A and B and the concentrations of glucose are unchanged. 
B)  The concentrations of glucose and sucrose are equal in sides A and B. 
C)  The concentration of glucose is equal in sides A and B and the concentrations of sucrose are unchanged. 
D)  The water levels change, but the concentrations of glucose and sucrose in sides A and B are unchanged.

Question 15

Figure 5.1
For the following questions, match the labeled component of the cell membrane in Figure 5.1 with its description.
-Which component in the figure plays an important role in cell-cell recognition?

Accepted Answer

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

Question 16

Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?

Accepted Answer

A)  Water will leave the cells, causing them to shrivel and collapse. 
B)  NaCl will be exported from the red blood cells by facilitated diffusion. 
C)  The blood cells will take up water, swell, and eventually burst. 
D)  NaCl will passively diffuse into the red blood cells. 
A)  Water will leave the cells, causing them to shrivel and collapse. 
B)  NaCl will be exported from the red blood cells by facilitated diffusion. 
C)  The blood cells will take up water, swell, and eventually burst. 
D)  NaCl will passively diffuse into the red blood cells.

Question 17

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling?

Accepted Answer

A)  decreased ATP production in aged cells 
B)  decreased hormone production in aged cells 
C)  decreased affinity of growth factor receptors for their respective ligands 
D)  decreased numbers of cytoplasmic ribosomes 
A)  decreased ATP production in aged cells 
B)  decreased hormone production in aged cells 
C)  decreased affinity of growth factor receptors for their respective ligands 
D)  decreased numbers of cytoplasmic ribosomes

Question 18

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?

Accepted Answer

A)  Proton pumps must have evolved before any living organisms were present on Earth. 
B)  Proton pumps are an essential feature of all cell membranes. 
C)  Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. 
D)  Cells of each domain evolved proton pumps independently when oceans became more acidic. 
A)  Proton pumps must have evolved before any living organisms were present on Earth. 
B)  Proton pumps are an essential feature of all cell membranes. 
C)  Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. 
D)  Cells of each domain evolved proton pumps independently when oceans became more acidic.

Question 19

Figure 5.1
For the following questions, match the labeled component of the cell membrane in Figure 5.1 with its description.
-Which component in the figure is a microfilament of the cytoskeleton?

Accepted Answer

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

Question 20

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?

Accepted Answer

A)  lower cytoplasmic levels of cAMP 
B)  an increase in receptor tyrosine kinase activity 
C)  a decrease in transcriptional activity of certain genes 
D)  a decrease in G protein activity 
A)  lower cytoplasmic levels of cAMP 
B)  an increase in receptor tyrosine kinase activity 
C)  a decrease in transcriptional activity of certain genes 
D)  a decrease in G protein activity

Exam 5: Membrane Transport and Cell Signaling

What is the voltage across a membrane called?

Submerging a red blood cell in distilled water will result in

The cell membranes of Antarctic ice fish might have which of the following adaptations?

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Figure 5.1 For the following questions, match the labeled component of the cell membrane in Figure 5.1 with its description. -Which component in the figure is a fiber of the extracellular matrix?

Celery stalks that are immersed in fresh water for several hours become turgid (stiff). Celery stalks left in a 0.15 M salt solution become flaccid (limp). From this we can deduce that

When biological membranes are frozen and then fractured, they tend to break along the middle of the bilayer. The best explanation for this is that

In what way do the membranes of a eukaryotic cell vary?

The primary function of G proteins in signal transduction is

The sodium-potassium pump generates the following concentration gradients across the plasma membrane:

The mechanism by which testosterone alters cell function is by

What kinds of molecules pass through a cell membrane most easily?

Which of the following statements correctly describes the normal tonicity relationships between typical plant and animal cells and their respective environments?

Figure 5.1 For the following questions, match the labeled component of the cell membrane in Figure 5.1 with its description. -Which component in the figure plays an important role in cell-cell recognition?

Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling?

Proton pumps are used in various ways by members of every domain of organisms: Bacteria, Archaea, and Eukarya. What does this most probably mean?

Figure 5.1 For the following questions, match the labeled component of the cell membrane in Figure 5.1 with its description. -Which component in the figure is a microfilament of the cytoskeleton?

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

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

Development, Stem Cells, and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition, Nutrition, and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons, Synapses, and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Species Interactions

Ecosystems and Energy

Global Ecology and Conservation Biology

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