Question 1

A steroid hormone would most likely enter a cell by:

Accepted Answer

A) active transport. 
B) osmosis. 
C) facilitated diffusion. 
D) vesicle-mediated transport. 
E) simple diffusion. 
A) active transport. 
B) osmosis. 
C) facilitated diffusion. 
D) vesicle-mediated transport. 
E) simple diffusion. E

Question 2

In plasmolysis:

Accepted Answer

A) the vacuole become turgid. 
B) the entire cell becomes turgid. 
C) the cell wall shrivels into the center of the cytoplasm. 
D) the plasma membrane pulls away from the cell wall. 
E) the plasma membrane is pushed against the cell wall. 
A) the vacuole become turgid. 
B) the entire cell becomes turgid. 
C) the cell wall shrivels into the center of the cytoplasm. 
D) the plasma membrane pulls away from the cell wall. 
E) the plasma membrane is pushed against the cell wall. D

Question 3

A cell that ingests bacteria or cellular debris does so by:

Accepted Answer

A) exocytosis. 
B) phagocytosis. 
C) pinocytosis. 
D) receptor-mediated endocytosis. 
E) facilitated diffusion. 
A) exocytosis. 
B) phagocytosis. 
C) pinocytosis. 
D) receptor-mediated endocytosis. 
E) facilitated diffusion. B

Question 4

Which of the following is NOT a function of membrane proteins?

Accepted Answer

A) converting energy from one form to another 
B) catalyzing chemical reactions 
C) transporting specific molecules or ions into and out of the cell 
D) making the membrane impermeable 
E) acting as receptors for chemical signals 
A) converting energy from one form to another 
B) catalyzing chemical reactions 
C) transporting specific molecules or ions into and out of the cell 
D) making the membrane impermeable 
E) acting as receptors for chemical signals

Question 5

Although membranes were previously described by the "fluid-mosaic" model, recent evidence suggests that membranes:

Accepted Answer

A) have lipids that are more widely dispersed and not grouped. 
B) have proteins that are not organized in functional complexes. 
C) have a smaller proportion of proteins. 
D) have a more constant thickness. 
E) are less fluid. 
A) have lipids that are more widely dispersed and not grouped. 
B) have proteins that are not organized in functional complexes. 
C) have a smaller proportion of proteins. 
D) have a more constant thickness. 
E) are less fluid.

Question 6

What is the water potential, expressed in units of megapascals, of pure water?

Accepted Answer

A) -10 
B) -5 
C) 0 
D) 10 
E) 20 
A) -10 
B) -5 
C) 0 
D) 10 
E) 20

Question 7

Which of the following statements concerning the desmotubule is FALSE?

Accepted Answer

A) It has the appearance of a tubular strand. 
B) It may contain a central rod. 
C) It is continuous with the endoplasmic of adjacent cells. 
D) It is a main channel for transporting materials. 
E) It is found within a plasmodesma. 
A) It has the appearance of a tubular strand. 
B) It may contain a central rod. 
C) It is continuous with the endoplasmic of adjacent cells. 
D) It is a main channel for transporting materials. 
E) It is found within a plasmodesma.

Question 8

Water moves from a region where water potential is higher to a region where it is lower.

Accepted Answer

A) True 
 B)False

Question 9

In the plasma membrane, carbohydrates are most likely to be found:

Accepted Answer

A) attached to phospholipids in the bilayer. 
B) attached to cholesterol in the bilayer. 
C) attached to a desmotubule in the bilayer. 
D) on the outer membrane surface. 
E) on the inner membrane surface. 
A) attached to phospholipids in the bilayer. 
B) attached to cholesterol in the bilayer. 
C) attached to a desmotubule in the bilayer. 
D) on the outer membrane surface. 
E) on the inner membrane surface.

Question 10

By definition, all proteins attached to protruding portions of transmembrane proteins are:

Accepted Answer

A) transmembrane proteins. 
B) integral proteins. 
C) globular proteins. 
D) peripheral proteins. 
E) glycoproteins. 
A) transmembrane proteins. 
B) integral proteins. 
C) globular proteins. 
D) peripheral proteins. 
E) glycoproteins.

Question 11

The most abundant sterol in the plant cell membrane is:

Accepted Answer

A) lectin. 
B) cholesterol. 
C) triglyceride. 
D) stigmasterol. 
E) phospholipid 
A) lectin. 
B) cholesterol. 
C) triglyceride. 
D) stigmasterol. 
E) phospholipid

Question 12

Which of the following statements concerning membrane structure is FALSE?

Accepted Answer

A) Some proteins are firmly anchored in place. 
B) Some proteins move laterally within the membrane. 
C) Some lipids move laterally within the membrane. 
D) Transmembrane proteins lack hydrophilic sequences. 
E) Peripheral proteins lack hydrophobic sequences. 
A) Some proteins are firmly anchored in place. 
B) Some proteins move laterally within the membrane. 
C) Some lipids move laterally within the membrane. 
D) Transmembrane proteins lack hydrophilic sequences. 
E) Peripheral proteins lack hydrophobic sequences.

Question 13

The transport of solutes by carrier proteins is faster than that by channel proteins.

Accepted Answer

A) True 
 B)False

Question 14

Which of the following statements about an electrochemical gradient is FALSE?

Accepted Answer

A) It involves a concentration gradient and the membrane potential. 
B) It involves a concentration gradient and the total electrical gradient. 
C) It is the driving force for the movement of charged and uncharged substances across a membrane. 
D) Plant cells maintain an electrochemical gradient across the plasma membrane. 
E) Plant cells maintain an electrochemical gradient across the tonoplast. 
A) It involves a concentration gradient and the membrane potential. 
B) It involves a concentration gradient and the total electrical gradient. 
C) It is the driving force for the movement of charged and uncharged substances across a membrane. 
D) Plant cells maintain an electrochemical gradient across the plasma membrane. 
E) Plant cells maintain an electrochemical gradient across the tonoplast.

Question 15

Unlike active transport, passive transport across cellular membranes does not require the participation of transport proteins.

Accepted Answer

A) True 
 B)False

Question 16

Receptor-mediated endocytosis involves the vesicle-mediated transport of specific molecules.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following would NOT occur during signal recognition?

Accepted Answer

A) The signal molecule binds to a specific receptor on the plasma membrane. 
B) The signal molecule is transported into the cell by endocytosis. 
C) The signal molecule is transported out of the cell by exocytosis. 
D) The signal molecule remains outside the cell. 
E) The signal molecule activates a transmembrane protein. 
A) The signal molecule binds to a specific receptor on the plasma membrane. 
B) The signal molecule is transported into the cell by endocytosis. 
C) The signal molecule is transported out of the cell by exocytosis. 
D) The signal molecule remains outside the cell. 
E) The signal molecule activates a transmembrane protein.

Question 18

In the plasma membrane, multipass proteins typically span the bilayer as alpha-helices.

Accepted Answer

A) True 
 B)False

Question 19

Primary plasmodesmata are different from secondary plasmodesmata in that primary plasmodesmata:

Accepted Answer

A) are narrow strands of cytoplasm. 
B) are formed during cytokinesis. 
C) are typically branched. 
D) connect the protoplasts of neighboring cells. 
E) may be connected by a cavity in the region of the middle lamella. 
A) are narrow strands of cytoplasm. 
B) are formed during cytokinesis. 
C) are typically branched. 
D) connect the protoplasts of neighboring cells. 
E) may be connected by a cavity in the region of the middle lamella.

Question 20

If the concentration of K+ is higher outside a plant cell than inside, K+ will enter the cell by:

Accepted Answer

A) facilitated diffusion through channel proteins. 
B) simple diffusion through channel proteins. 
C) facilitated diffusion via carrier proteins. 
D) active transport through channel proteins. 
E) active transport via carrier proteins. 
A) facilitated diffusion through channel proteins. 
B) simple diffusion through channel proteins. 
C) facilitated diffusion via carrier proteins. 
D) active transport through channel proteins. 
E) active transport via carrier proteins.

Exam 4: The Movement of Substances Into and Out of Cells

A steroid hormone would most likely enter a cell by:

In plasmolysis:

A cell that ingests bacteria or cellular debris does so by:

Which of the following is NOT a function of membrane proteins?

Although membranes were previously described by the "fluid-mosaic" model, recent evidence suggests that membranes:

What is the water potential, expressed in units of megapascals, of pure water?

Which of the following statements concerning the desmotubule is FALSE?

Water moves from a region where water potential is higher to a region where it is lower.

In the plasma membrane, carbohydrates are most likely to be found:

By definition, all proteins attached to protruding portions of transmembrane proteins are:

The most abundant sterol in the plant cell membrane is:

Which of the following statements concerning membrane structure is FALSE?

The transport of solutes by carrier proteins is faster than that by channel proteins.

Which of the following statements about an electrochemical gradient is FALSE?

Unlike active transport, passive transport across cellular membranes does not require the participation of transport proteins.

Receptor-mediated endocytosis involves the vesicle-mediated transport of specific molecules.

Which of the following would NOT occur during signal recognition?

In the plasma membrane, multipass proteins typically span the bilayer as alpha-helices.

Primary plasmodesmata are different from secondary plasmodesmata in that primary plasmodesmata:

If the concentration of K+ is higher outside a plant cell than inside, K+ will enter the cell by:

Botany: an Introduction

The Molecular Composition of Plant Cells

The Plant Cell and the Cell Cycle

The Flow of Energy

Respiration

Photosynthesis, Light, and Life

Sexual Reproduction and Heredity

The Chemistry of Heredity and Gene Expression

Recombinant Dna Technology, Plant Biotechnology, and Genomics

The Process of Evolution

Systematics: the Science of Biological Diversity

Prokaryotes and Viruses

Fungi

Protists: Algae and Heterotrophic Protists

Bryophytes

Seedless Vascular Plants

Gymnosperms

Introduction to the Angiosperms

Evolution of the Angiosperms

Plants and People

Early Development of the Plant Body

Cells and Tissues of the Plant Body

The Root: Structure and Development

The Shoot: Primary Structure and Development

Secondary Growth in Stems

Regulating Growth and Development: the Plant Hormones

External Factors and Plant Growth

Plant Nutrition and Soils

The Movement of Water and Solutes in Plants

The Dynamics of Communities and Ecosystems

Global Ecology

Filters

If the concentration of K⁺ is higher outside a plant cell than inside, K⁺ will enter the cell by: