Question 1

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 2

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

Accepted Answer

A) True 
 B)False

Question 3

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 4

Passive diffusion can occur down a concentration gradient but not down an electrochemical gradient.

Accepted Answer

A) True 
 B)False

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

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.

Question 7

Two of the most common second messengers are:

Accepted Answer

A)  hormones and ATP. 
B)  ATP and cyclic AMP. 
C)  calcium ions and cyclic AMP. 
D)  lectins and calcium ions. 
E)  lectins and clathrin. 
A)  hormones and ATP. 
B)  ATP and cyclic AMP. 
C)  calcium ions and cyclic AMP. 
D)  lectins and calcium ions. 
E)  lectins and clathrin.

Question 8

If the concentration of glucose is higher inside a cell than outside, glucose will enter the cell only by:

Accepted Answer

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

Question 9

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.

Question 10

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 11

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 12

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 13

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

Accepted Answer

A) True 
 B)False

Question 14

Aquaporins are found in the plasma membrane and the:

Accepted Answer

A)  inner mitochondrial membrane only. 
B)  inner chloroplast membrane only 
C)  tonoplast only. 
D)  endoplasmic reticulum only. 
E)  the mitochondrial membrane, the chloroplast membrane, the tonoplast, and the ER. 
A)  inner mitochondrial membrane only. 
B)  inner chloroplast membrane only 
C)  tonoplast only. 
D)  endoplasmic reticulum only. 
E)  the mitochondrial membrane, the chloroplast membrane, the tonoplast, and the ER.

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

Which of the following statements concerning plasmodesmata is FALSE?

Accepted Answer

A)  They can mediate the transport of proteins and RNA. 
B)  Their openings can be regulated by actin and myosin.. 
C)  They serve as paths for electrical signaling. 
D)  Their permeability can be controlled by callose. 
E)  Their similar symplastic domains cause them to be passive structures. 
A)  They can mediate the transport of proteins and RNA. 
B)  Their openings can be regulated by actin and myosin.. 
C)  They serve as paths for electrical signaling. 
D)  Their permeability can be controlled by callose. 
E)  Their similar symplastic domains cause them to be passive structures.

Question 17

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 18

In receptor-mediated endocytosis, what happens immediately after the substance to be transported binds to a receptor?

Accepted Answer

A)  The substance is broken down enzymatically. 
B)  The coated pit invaginates to form a coated vesicle. 
C)  The receptor releases the substance inside the cell. 
D)  The coated vesicle sheds its coat. 
E)  The receptor is broken down enzymatically. 
A)  The substance is broken down enzymatically. 
B)  The coated pit invaginates to form a coated vesicle. 
C)  The receptor releases the substance inside the cell. 
D)  The coated vesicle sheds its coat. 
E)  The receptor is broken down enzymatically.

Question 19

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 20

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

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

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

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

Which of the following statements about diffusion is FALSE?

Passive diffusion can occur down a concentration gradient but not down an electrochemical gradient.

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

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

Two of the most common second messengers are:

If the concentration of glucose is higher inside a cell than outside, glucose will enter the cell only by:

A steroid hormone would most likely enter a cell by:

Wall pressure:

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

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

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

Aquaporins are found in the plasma membrane and the:

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

Which of the following statements concerning plasmodesmata is FALSE?

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

In receptor-mediated endocytosis, what happens immediately after the substance to be transported binds to a receptor?

Which of the following statements concerning the desmotubule is FALSE?

The most abundant sterol in the plant cell membrane is:

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: