Question 1

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 C

Question 2

A research team is working on the design of a new drug for the treatment of lung cancer. To be most effective, this drug must specifically enter the cytoplasm of lung cells while not entering the cells of other tissues. Which of the following characteristics would likely enhance the specificity of this drug?

Accepted Answer

A)  the relative hydrophobicity of the drug molecule 
B)  phospholipid composition of lung cell plasma membranes 
C)  specificity of the drug molecule for binding to the extracellular matrix of lung cells 
D)  similarity of the drug molecule to other molecules normally transported lung cells 
A)  the relative hydrophobicity of the drug molecule 
B)  phospholipid composition of lung cell plasma membranes 
C)  specificity of the drug molecule for binding to the extracellular matrix of lung cells 
D)  similarity of the drug molecule to other molecules normally transported lung cells D

Question 3

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.
 
In the U-tube illustrated above, ________.

Accepted Answer

A)  side A is hypertonic to side B 
B)  side A is hypotonic to side B 
C)  side A is isotonic to side B 
D)  side A is more turgid than side B 
A)  side A is hypertonic to side B 
B)  side A is hypotonic to side B 
C)  side A is isotonic to side B 
D)  side A is more turgid than side B C

Question 4

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 5

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane?

Accepted Answer

A)  large hydrophobic molecules 
B)  small hydrophobic molecules 
C)  carbon dioxide 
D)  small ions 
A)  large hydrophobic molecules 
B)  small hydrophobic molecules 
C)  carbon dioxide 
D)  small ions

Question 6

Which of the following processes includes all the others?

Accepted Answer

A)  osmosis 
B)  diffusion of a solute across a membrane 
C)  passive transport 
D)  transport of an ion down its electrochemical gradient 
A)  osmosis 
B)  diffusion of a solute across a membrane 
C)  passive transport 
D)  transport of an ion down its electrochemical gradient

Question 7

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 8

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

Question 9

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

Accepted Answer

A)  It exhibits specificity for a particular type of molecule. 
B)  It requires the expenditure of cellular energy to function. 
C)  It works against diffusion. 
D)  It has no hydrophobic regions. 
A)  It exhibits specificity for a particular type of molecule. 
B)  It requires the expenditure of cellular energy to function. 
C)  It works against diffusion. 
D)  It has no hydrophobic regions.

Question 10

Which of the following factors would tend to increase membrane fluidity?

Accepted Answer

A)  a greater proportion of unsaturated phospholipids 
B)  a greater proportion of saturated phospholipids 
C)  a lower temperature 
D)  a relatively high protein content in the membrane 
A)  a greater proportion of unsaturated phospholipids 
B)  a greater proportion of saturated phospholipids 
C)  a lower temperature 
D)  a relatively high protein content in the membrane

Question 11

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

Question 12

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

Accepted Answer

A)  Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. 
B)  The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. 
C)  Cells of each domain evolved proton pumps independently when oceans became more acidic. 
D)  Proton pumps are necessary to all cell membranes. 
A)  Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life. 
B)  The high concentration of protons in the ancient atmosphere must have necessitated a pump mechanism. 
C)  Cells of each domain evolved proton pumps independently when oceans became more acidic. 
D)  Proton pumps are necessary to all cell membranes.

Question 13

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 that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment?

Accepted Answer

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

Question 14

Which of the following would likely diffuse through the lipid bilayer of a plasma membrane most rapidly?

Accepted Answer

A)  sucrose 
B)  an amino acid 
C)  O₂ 
D)  Na⁺ 
A)  sucrose 
B)  an amino acid 
C)  O₂ 
D)  Na⁺

Question 15

The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane-more acidic outside the cell than inside the cell. In this bacterial cell, phosphate transport is an example of ________.

Accepted Answer

A)  passive diffusion 
B)  facilitated diffusion 
C)  active transport 
D)  cotransport 
A)  passive diffusion 
B)  facilitated diffusion 
C)  active transport 
D)  cotransport

Question 16

In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis?

Accepted Answer

A)  on the outside of vesicles 
B)  on the inside surface of the cell membrane 
C)  on the inside surface of the vesicle 
D)  on the outer surface of the nucleus 
A)  on the outside of vesicles 
B)  on the inside surface of the cell membrane 
C)  on the inside surface of the vesicle 
D)  on the outer surface of the nucleus

Question 17

Which of the following statements correctly describes osmosis?

Accepted Answer

A)  Osmosis only takes place in red blood cells. 
B)  Osmosis is an energy-demanding or "active" process. 
C)  In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. 
D)  In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration. 
A)  Osmosis only takes place in red blood cells. 
B)  Osmosis is an energy-demanding or "active" process. 
C)  In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. 
D)  In osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration.

Question 18

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 19

Based on Figure 7.18, which of these experimental treatments would increase the rate of sucrose transport into a plant cell?

Accepted Answer

A)  decreasing extracellular sucrose concentration 
B)  decreasing extracellular pH 
C)  decreasing cytoplasmic pH 
D)  adding a substance that makes the membrane more permeable to hydrogen ions 
A)  decreasing extracellular sucrose concentration 
B)  decreasing extracellular pH 
C)  decreasing cytoplasmic pH 
D)  adding a substance that makes the membrane more permeable to hydrogen ions

Question 20

Why are lipids and proteins free to move laterally in membranes?

Accepted Answer

A)  The interior of the membrane is filled with liquid water. 
B)  Lipids and proteins repulse each other in the membrane. 
C)  Hydrophilic portions of the lipids are in the interior of the membrane. 
D)  There are only weak hydrophobic interactions in the interior of the membrane. 
A)  The interior of the membrane is filled with liquid water. 
B)  Lipids and proteins repulse each other in the membrane. 
C)  Hydrophilic portions of the lipids are in the interior of the membrane. 
D)  There are only weak hydrophobic interactions in the interior of the membrane.

Exam 7: Membrane Structure and Function

Which of the following processes includes all of the others?

Familial hypercholesterolemia is characterized by ________.

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane?

Which of the following processes includes all the others?

According to the fluid mosaic model, a membrane ________.

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

Which of the following factors would tend to increase membrane fluidity?

The voltage across a membrane is called the ________.

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

Which of the following would likely diffuse through the lipid bilayer of a plasma membrane most rapidly?

In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis?

Which of the following statements correctly describes osmosis?

White blood cells engulf bacteria using ________.

Based on Figure 7.18, which of these experimental treatments would increase the rate of sucrose transport into a plant cell?

Why are lipids and proteins free to move laterally in membranes?

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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