Question 1

The steeper the concentration gradient, the more rapid the rate of diffusion.

Accepted Answer

A) True 
 B)False

Question 2

When botanists speak of a "bilayer," they are referring to a structure composed entirely of:

Accepted Answer

A) carbohydrates. 
B) integral proteins. 
C) lectins. 
D) sterols. 
E) phospholipids. 
A) carbohydrates. 
B) integral proteins. 
C) lectins. 
D) sterols. 
E) phospholipids.

Question 3

All the membranes of a cell have the same basic structure.

Accepted Answer

A) True 
 B)False

Question 4

The apoplast consists of all the interconnected protoplasts of the plant body together with their plasmodesmata.

Accepted Answer

A) True 
 B)False

Question 5

If a plant cell is placed in a solution with a relatively low water potential, the cell will:

Accepted Answer

A) swell and perhaps burst. 
B) undergo plasmolysis. 
C) build up turgor pressure. 
D) build up wall pressure. 
E) neither gain nor lose water. 
A) swell and perhaps burst. 
B) undergo plasmolysis. 
C) build up turgor pressure. 
D) build up wall pressure. 
E) neither gain nor lose water.

Question 6

In the plasma membrane, proteins can move laterally but lipids cannot.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following substances is LEAST likely to diffuse across the plasma membrane?

Accepted Answer

A) water 
B) a small, uncharged polar molecule 
C) an ion 
D) carbon dioxide 
E) oxygen 
A) water 
B) a small, uncharged polar molecule 
C) an ion 
D) carbon dioxide 
E) oxygen

Question 8

In receptor-mediated endocytosis, specific receptors for the substances to be transported are localized in:

Accepted Answer

A) the nucleus. 
B) Golgi bodies. 
C) mitochondria. 
D) the cytoplasm. 
E) coated pits. 
A) the nucleus. 
B) Golgi bodies. 
C) mitochondria. 
D) the cytoplasm. 
E) coated pits.

Question 9

Typically a second messenger is located on the outside, rather than the inside, of a cell.

Accepted Answer

A) True 
 B)False

Question 10

An aquaporin is a:

Accepted Answer

A) hole in a water molecule. 
B) channel protein for water. 
C) carrier protein for water. 
D) protein that binds water inside the cytosol. 
E) carbohydrate that binds water to prevent bursting of the cell. 
A) hole in a water molecule. 
B) channel protein for water. 
C) carrier protein for water. 
D) protein that binds water inside the cytosol. 
E) carbohydrate that binds water to prevent bursting of the cell.

Question 11

The rate of osmosis is influenced by the size of the solute particle.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following is the best definition of osmosis?

Accepted Answer

A) The net movement of glucose across a selectively permeable membrane. 
B) The net movement of any substance down a solute concentration gradient. 
C) The net movement of water across a selectively permeable membrane. 
D) The net movement of water from a region of high water potential to a region of low water potential. 
E) The net movement of water from a region of low water potential to a region of high water potential. 
A) The net movement of glucose across a selectively permeable membrane. 
B) The net movement of any substance down a solute concentration gradient. 
C) The net movement of water across a selectively permeable membrane. 
D) The net movement of water from a region of high water potential to a region of low water potential. 
E) The net movement of water from a region of low water potential to a region of high water potential.

Question 13

Which of the following processes in plant cell membranes requires ATP?

Accepted Answer

A) simple diffusion 
B) facilitated diffusion 
C) osmosis 
D) passive cotransport 
E) active transport 
A) simple diffusion 
B) facilitated diffusion 
C) osmosis 
D) passive cotransport 
E) active transport

Question 14

The portion of a transmembrane protein that is embedded in the hydrophobic interior of the bilayer is usually in the form of a(n):

Accepted Answer

A) beta pleated sheet. 
B) alpha helix. 
C) alpha helix and beta pleated sheet combined. 
D) extended polypeptide without secondary structure. 
E) folded polypeptide without secondary structure. 
A) beta pleated sheet. 
B) alpha helix. 
C) alpha helix and beta pleated sheet combined. 
D) extended polypeptide without secondary structure. 
E) folded polypeptide without secondary structure.

Question 15

Which of the following statements about solute movement in cells is FALSE?

Accepted Answer

A) Once a substance is inside a cell, it moves through the cell by diffusion. 
B) Diffusion is an effective way to move substances between distantly separated cells. 
C) Transport of substances within a cell may be speeded up by cytoplasmic streaming. 
D) Metabolic activities help maintain steep concentration gradients between the inside and outside of the cell. 
E) Within a cell, a substance may be produced in one place and used in another, thus maintaining an intracellular concentration gradient. 
A) Once a substance is inside a cell, it moves through the cell by diffusion. 
B) Diffusion is an effective way to move substances between distantly separated cells. 
C) Transport of substances within a cell may be speeded up by cytoplasmic streaming. 
D) Metabolic activities help maintain steep concentration gradients between the inside and outside of the cell. 
E) Within a cell, a substance may be produced in one place and used in another, thus maintaining an intracellular concentration gradient.

Question 16

Which of the following statements about diffusion is FALSE?

Accepted Answer

A) When the diffusing molecules become evenly distributed, their movement stops. 
B) Each of the diffusing molecules moves randomly and independently of the others. 
C) It is more rapid at higher than at lower temperatures. 
D) It involves the net movement of a substance. 
E) It is more rapid in gases than in liquids. 
A) When the diffusing molecules become evenly distributed, their movement stops. 
B) Each of the diffusing molecules moves randomly and independently of the others. 
C) It is more rapid at higher than at lower temperatures. 
D) It involves the net movement of a substance. 
E) It is more rapid in gases than in liquids.

Question 17

Wall pressure:

Accepted Answer

A) is the same as turgor pressure. 
B) develops within a cell and pushes outward against the wall. 
C) develops outside the cell wall and pushes inward against the wall. 
D) is an outwardly directed pressure of the wall. 
E) is an inwardly directed pressure of the wall. 
A) is the same as turgor pressure. 
B) develops within a cell and pushes outward against the wall. 
C) develops outside the cell wall and pushes inward against the wall. 
D) is an outwardly directed pressure of the wall. 
E) is an inwardly directed pressure of the wall.

Question 18

Cholesterol is the major sterol in the plasma membrane of plant cells.

Accepted Answer

A) True 
 B)False

Question 19

The cytoplasmic sleeve is the:

Accepted Answer

A) cytoplasmic channel involved in symplastic transport through a plasmodesma. 
B) cytoplasm inside the lumen of a desmotubule. 
C) cytoplasm in the cortical area of the protoplast. 
D) cytoplasm inside the endoplasmic reticulum. 
E) extension of the cytoplasm into the cell wall. 
A) cytoplasmic channel involved in symplastic transport through a plasmodesma. 
B) cytoplasm inside the lumen of a desmotubule. 
C) cytoplasm in the cortical area of the protoplast. 
D) cytoplasm inside the endoplasmic reticulum. 
E) extension of the cytoplasm into the cell wall.

Question 20

In the signal-transduction pathway involving Ca2+ ions in plants, which of the following occurs during the transduction step?

Accepted Answer

A) The chemical signal binds to the receptor. 
B) The Ca2+-calmodulin complex activates specific enzymes. 
C) Clathrin binds to Ca2+ ions. 
D) Calcium ions are released into the cytosol from the vacuole. 
E) Calcium ions bind to calmodulin. 
A) The chemical signal binds to the receptor. 
B) The Ca2+-calmodulin complex activates specific enzymes. 
C) Clathrin binds to Ca2+ ions. 
D) Calcium ions are released into the cytosol from the vacuole. 
E) Calcium ions bind to calmodulin.

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

The steeper the concentration gradient, the more rapid the rate of diffusion.

When botanists speak of a "bilayer," they are referring to a structure composed entirely of:

All the membranes of a cell have the same basic structure.

The apoplast consists of all the interconnected protoplasts of the plant body together with their plasmodesmata.

If a plant cell is placed in a solution with a relatively low water potential, the cell will:

In the plasma membrane, proteins can move laterally but lipids cannot.

Which of the following substances is LEAST likely to diffuse across the plasma membrane?

In receptor-mediated endocytosis, specific receptors for the substances to be transported are localized in:

Typically a second messenger is located on the outside, rather than the inside, of a cell.

An aquaporin is a:

The rate of osmosis is influenced by the size of the solute particle.

Which of the following is the best definition of osmosis?

Which of the following processes in plant cell membranes requires ATP?

The portion of a transmembrane protein that is embedded in the hydrophobic interior of the bilayer is usually in the form of a(n):

Which of the following statements about solute movement in cells is FALSE?

Which of the following statements about diffusion is FALSE?

Wall pressure:

Cholesterol is the major sterol in the plasma membrane of plant cells.

The cytoplasmic sleeve is the:

In the signal-transduction pathway involving Ca2+ ions in plants, which of the following occurs during the transduction step?

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

In the signal-transduction pathway involving Ca²⁺ ions in plants, which of the following occurs during the transduction step?