Question 1

Microtubules and microfilaments differ with respect to each of the following except

Accepted Answer

A) size. 
B) occurrence. 
C) associated motor proteins. 
D) a state of dynamic instability. 
E) subunits. 
A) size. 
B) occurrence. 
C) associated motor proteins. 
D) a state of dynamic instability. 
E) subunits. D

Question 2

Rho GTPases have the all of the following effects on cytoskeletal actin except

Accepted Answer

A) stress fiber formation. 
B) formation of pseudopodia. 
C) stabilization of neurons. 
D) assembly of the cytokinetic furrow. 
E) regulation of endocytosis and exocytosis. 
A) stress fiber formation. 
B) formation of pseudopodia. 
C) stabilization of neurons. 
D) assembly of the cytokinetic furrow. 
E) regulation of endocytosis and exocytosis. C

Question 3

F-actin filaments

Accepted Answer

A) are composed of four linear strands. 
B) are composed of polymerized G-actin monomers wound around each other in a helix. 
C) are oriented similar to DNA, with strands helical and antiparallel to one another. 
D) are composed of G-actin dimers. 
E) polymerize at the same rate in both directions from both ends of the filament. 
A) are composed of four linear strands. 
B) are composed of polymerized G-actin monomers wound around each other in a helix. 
C) are oriented similar to DNA, with strands helical and antiparallel to one another. 
D) are composed of G-actin dimers. 
E) polymerize at the same rate in both directions from both ends of the filament. B

Question 4

Choose the item that best matches the other items.
-microvilli

Accepted Answer

A) breaking and capping actin 
B) increase cellular surface area 
C) assembly and disassembly 
D) terminal web 
E) control microtubule organization
F)plectin
G)central shaft
H)nucleating actin branches
I)bind to profilin and CapZ
J)oligomer formation
K)nucleating tubulin branches
L)hemidesmosome
M)decorate the actin microfilament
N)dynein
O)prevents loss of subunits
P)desmosome  
Q)nuclear lamina  
R)account for 10-15% of microtubules  
S)inhibits microtubule assembly  
T)two identical polypeptides joined end-to-end  
U)found in cilia and flagella 
A) breaking and capping actin 
B) increase cellular surface area 
C) assembly and disassembly 
D) terminal web 
E) control microtubule organization
F)plectin
G)central shaft
H)nucleating actin branches
I)bind to profilin and CapZ
J)oligomer formation
K)nucleating tubulin branches
L)hemidesmosome
M)decorate the actin microfilament
N)dynein
O)prevents loss of subunits
P)desmosome  
Q)nuclear lamina  
R)account for 10-15% of microtubules  
S)inhibits microtubule assembly  
T)two identical polypeptides joined end-to-end  
U)found in cilia and flagella

Question 5

Axonemal microtubules

Accepted Answer

A) are highly disorganized but very stable. 
B) may be loosely associated with basal bodies. 
C) are organized around a central shaft or axoneme. 
D) are required to maintain axons. 
E) did not become clearly recognized until better fixation techniques became available in the 1960s. 
A) are highly disorganized but very stable. 
B) may be loosely associated with basal bodies. 
C) are organized around a central shaft or axoneme. 
D) are required to maintain axons. 
E) did not become clearly recognized until better fixation techniques became available in the 1960s.

Question 6

Of the following proteins,which would be a good target for drug therapy if one needed to interfere with breaking down the microfilament network?

Accepted Answer

A) profilin 
B) CapZ 
C) gelsolin 
D) tropomodulin 
E) calmodulin 
A) profilin 
B) CapZ 
C) gelsolin 
D) tropomodulin 
E) calmodulin

Question 7

A variety of proteins link actin to membranes.A ________ protein is used to link actin to the ________ membrane.

Accepted Answer

A) linker; plasma 
B) spectrin; ER 
C) ankyrin; lysosome 
D) band 4.1; basal 
E) band 4.1; mucous 
A) linker; plasma 
B) spectrin; ER 
C) ankyrin; lysosome 
D) band 4.1; basal 
E) band 4.1; mucous

Question 8

Intermediate filaments

Accepted Answer

A) were first discovered in muscle cells. 
B) are grouped into five classes based on the cell types in which they are found. 
C) have molecular masses averaging 500 kDa. 
D) are smooth and sticky. 
E) assemble from nonfibrous filaments. 
A) were first discovered in muscle cells. 
B) are grouped into five classes based on the cell types in which they are found. 
C) have molecular masses averaging 500 kDa. 
D) are smooth and sticky. 
E) assemble from nonfibrous filaments.

Question 9

All of the following are components associated with the bacterial cytoskeleton except

Accepted Answer

A) FtsZ. 
B) MreB. 
C) plaktin. 
D) crescentin. 
E) both choices B and C 
A) FtsZ. 
B) MreB. 
C) plaktin. 
D) crescentin. 
E) both choices B and C

Question 10

Lamellipodia

Accepted Answer

A) are found in the basal lamina. 
B) add structural rigidity to cells. 
C) contain microtubules. 
D) are thin sheets of cytoplasm use for cell movement. 
E) do not involve actin or tubulin. 
A) are found in the basal lamina. 
B) add structural rigidity to cells. 
C) contain microtubules. 
D) are thin sheets of cytoplasm use for cell movement. 
E) do not involve actin or tubulin.

Question 11

Ring-shaped complexes in the centrosome contain ________ in combination with ________.

Accepted Answer

A) α-tubulin; cilium 
B) α-tubulin; γ-tubulin 
C) β-tubulin; tubulin GTP 
D) γ-tubulin; pericentrin 
E) γ-tubulin; tubulin GTP 
A) α-tubulin; cilium 
B) α-tubulin; γ-tubulin 
C) β-tubulin; tubulin GTP 
D) γ-tubulin; pericentrin 
E) γ-tubulin; tubulin GTP

Question 12

The microtubule-organizing center (MTOC)

Accepted Answer

A) serves as a site for microtubule and microfilament assembly. 
B) acts as an anchor for both ends of the microtubule. 
C) is associated with two centrioles in plant cells. 
D) is called a centrosome during interphase. 
E) is positioned near the cell membrane. 
A) serves as a site for microtubule and microfilament assembly. 
B) acts as an anchor for both ends of the microtubule. 
C) is associated with two centrioles in plant cells. 
D) is called a centrosome during interphase. 
E) is positioned near the cell membrane.

Question 13

The ________ is a dense network of microfilaments just beneath the plasma membrane.

Accepted Answer

The answer of The ________ is a dense network of...

Question 14

The structure,function,and assembly of microtubules are regulated by ________ proteins (MAPs).

Accepted Answer

microtubul

Question 15

Choose the item that best matches the other items.
-nucleation

Accepted Answer

A) breaking and capping actin 
B) increase cellular surface area 
C) assembly and disassembly 
D) terminal web 
E) control microtubule organization
F)plectin
G)central shaft
H)nucleating actin branches
I)bind to profilin and CapZ
J)oligomer formation
K)nucleating tubulin branches
L)hemidesmosome
M)decorate the actin microfilament
N)dynein
O)prevents loss of subunits
P)desmosome  
Q)nuclear lamina  
R)account for 10-15% of microtubules  
S)inhibits microtubule assembly  
T)two identical polypeptides joined end-to-end  
U)found in cilia and flagella 
A) breaking and capping actin 
B) increase cellular surface area 
C) assembly and disassembly 
D) terminal web 
E) control microtubule organization
F)plectin
G)central shaft
H)nucleating actin branches
I)bind to profilin and CapZ
J)oligomer formation
K)nucleating tubulin branches
L)hemidesmosome
M)decorate the actin microfilament
N)dynein
O)prevents loss of subunits
P)desmosome  
Q)nuclear lamina  
R)account for 10-15% of microtubules  
S)inhibits microtubule assembly  
T)two identical polypeptides joined end-to-end  
U)found in cilia and flagella

Question 16

Choose the item that best matches the other items.
-motor MAPs

Accepted Answer

A) breaking and capping actin 
B) increase cellular surface area 
C) assembly and disassembly 
D) terminal web 
E) control microtubule organization
F)plectin
G)central shaft
H)nucleating actin branches
I)bind to profilin and CapZ
J)oligomer formation
K)nucleating tubulin branches
L)hemidesmosome
M)decorate the actin microfilament
N)dynein
O)prevents loss of subunits
P)desmosome  
Q)nuclear lamina  
R)account for 10-15% of microtubules  
S)inhibits microtubule assembly  
T)two identical polypeptides joined end-to-end  
U)found in cilia and flagella 
A) breaking and capping actin 
B) increase cellular surface area 
C) assembly and disassembly 
D) terminal web 
E) control microtubule organization
F)plectin
G)central shaft
H)nucleating actin branches
I)bind to profilin and CapZ
J)oligomer formation
K)nucleating tubulin branches
L)hemidesmosome
M)decorate the actin microfilament
N)dynein
O)prevents loss of subunits
P)desmosome  
Q)nuclear lamina  
R)account for 10-15% of microtubules  
S)inhibits microtubule assembly  
T)two identical polypeptides joined end-to-end  
U)found in cilia and flagella

Question 17

Of the following microtubule-interacting proteins,which might you potentially investigate as a mechanism for disrupting cell division in actively replicating tumor cells?

Accepted Answer

A) Tau 
B) +-TIP proteins 
C) catastrophins 
D) G-actin 
E) FtsZ 
A) Tau 
B) +-TIP proteins 
C) catastrophins 
D) G-actin 
E) FtsZ

Question 18

Based on composition similarities,actin can be divided into two major groups: the muscle-specific actins (________-actin)and nonmuscle actins (________- and ________-actin).

Accepted Answer

The answer of Based on composition similarities,actin can be divided...

Question 19

Tubulin may assemble and disassemble simultaneously in a process known as

Accepted Answer

A) dynamic instability. 
B) treadmilling. 
C) microtubule organizing. 
D) MAP motoring. 
E) actin-regulated assembly. 
A) dynamic instability. 
B) treadmilling. 
C) microtubule organizing. 
D) MAP motoring. 
E) actin-regulated assembly.

Question 20

What is the importance of proteins that precisely control when and where cytoskeletal elements form and depolymerize? Make sure to give examples in your explanations.

Accepted Answer

They allow for precise control,orientati

Exam 15: Cytoskeletal Systems

Microtubules and microfilaments differ with respect to each of the following except

Rho GTPases have the all of the following effects on cytoskeletal actin except

F-actin filaments

Choose the item that best matches the other items. -microvilli

Axonemal microtubules

Of the following proteins,which would be a good target for drug therapy if one needed to interfere with breaking down the microfilament network?

A variety of proteins link actin to membranes.A ________ protein is used to link actin to the ________ membrane.

Intermediate filaments

All of the following are components associated with the bacterial cytoskeleton except

Lamellipodia

Ring-shaped complexes in the centrosome contain ________ in combination with ________.

The microtubule-organizing center (MTOC)

The ________ is a dense network of microfilaments just beneath the plasma membrane.

The structure,function,and assembly of microtubules are regulated by ________ proteins (MAPs).

Choose the item that best matches the other items. -nucleation

Choose the item that best matches the other items. -motor MAPs

Of the following microtubule-interacting proteins,which might you potentially investigate as a mechanism for disrupting cell division in actively replicating tumor cells?

Based on composition similarities,actin can be divided into two major groups: the muscle-specific actins (________-actin)and nonmuscle actins (________- and ________-actin).

Tubulin may assemble and disassemble simultaneously in a process known as

What is the importance of proteins that precisely control when and where cytoskeletal elements form and depolymerize? Make sure to give examples in your explanations.

A Preview of the Cell

The Chemistry of the Cell

The Macromolecules of the Cell

Cells and Organelles

Bioenergetics: the Flow of Energy in the Cell

Enzymes: the Catalysts of Life

Membranes: Their Structure, function, and Chemistry

Transport Across Membranes: Overcoming the Permeability Barrier

Chemotrophic Energy Metabolism: Glycolysis and Fermentation

Chemotrophic Energy Metabolism: Aerobic Respiration

Phototrophic Energy Metabolism: Photosynthesis

The Endomembrane System and Peroxisomes

Signal Transduction Mechanisms: Ielectrical and Synaptic Signaling in Neurons

Signal Transduction Mechanisms: Iimessengers and Receptors

Cellular Movement: Motility and Contractility

Beyond the Cell: Cell Adhesions, cell Junctions, and Extracellular Structures

The Structural Basis of Cellular Information: DNA, chromosomes, and the Nucleus

The Cell Cycle, DNA Replication, and Mitosis

Sexual Reproduction, meiosis, and Genetic Recombination

Gene Expression: Ithe Genetic Code and Transcription

Gene Expression: Iiprotein Synthesis and Sorting

The Regulation of Gene Expression

Cancer Cells

Filters

A variety of proteins link actin to membranes.A protein is used to link actin to the membrane.

Ring-shaped complexes in the centrosome contain in combination with .

Based on composition similarities,actin can be divided into two major groups: the muscle-specific actins (-actin)and nonmuscle actins (- and -actin).