Question 1

Elongation of the microtubule occurs by the

Accepted Answer

A) addition of tubulin subunits to each end. 
B) addition of tubulin subunits to the (+)end. 
C) addition of the tubulin subunits to the (+)end but removal from the (-)end. 
D) addition of G-actin subunits to the (+)end. 
E) deletion of G-actin subunits from the (+)end. 
A) addition of tubulin subunits to each end. 
B) addition of tubulin subunits to the (+)end. 
C) addition of the tubulin subunits to the (+)end but removal from the (-)end. 
D) addition of G-actin subunits to the (+)end. 
E) deletion of G-actin subunits from the (+)end.

Question 2

Microfilaments function in

Accepted Answer

A) muscle contraction. 
B) cytoplasmic streaming. 
C) cell division. 
D) maintenance of cellular shape in animal cells. 
E) all of the above 
A) muscle contraction. 
B) cytoplasmic streaming. 
C) cell division. 
D) maintenance of cellular shape in animal cells. 
E) all of the above

Question 3

Actin bundles give shape and support to the ________ found in cells of the small intestine.

Accepted Answer

A) centrosomes 
B) microtubules 
C) microvilli 
D) nuclei 
E) lamellipodia 
A) centrosomes 
B) microtubules 
C) microvilli 
D) nuclei 
E) lamellipodia

Question 4

In binary fission,one would expect the involvement of which of the following cytoskeletal proteins?

Accepted Answer

A) FtsZ 
B) MreB 
C) plaktin 
D) crescentin 
E) tubulin 
A) FtsZ 
B) MreB 
C) plaktin 
D) crescentin 
E) tubulin

Question 5

Choose the item that best matches the other items.
-capping protein

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 6

Based upon your knowledge of the cytoskeleton,explain how the discovery of cytoskeletal elements in prokaryotes contributed to the current understanding of the endosymbiont theory.

Accepted Answer

The discovery of progenitor proteins wit

Question 7

Activation of the ________ G-protein results in the formation of focal adhesions and stress fibers.

Accepted Answer

The answer of Activation of the ________ G-protein results in...

Question 8

The ________ model is used to describe the simultaneous polymerization and depolymerization of microtubules.

Accepted Answer

The answer of The ________ model is used to describe...

Question 9

The proteins of intermediate filaments (IFs)are tissue specific.Unlike microtubules or microfilaments,the amino acid composition of intermediate filaments varies from tissue to tissue.IFs are classified by the cell type or tissue in which they are found.
a. According to your text,how many classes of IF exist?
b. List the classes of IF,the IF proteins,and the tissue (or cells)in the table below.
   
c. Cells retain the IF proteins from the tissue of origin even after moving to other tissues.How is this important in the diagnosis and treatment of cancer?b.See both Table 15-4 and table below.

Accepted Answer

a. six
b. See both Table 15-4

Question 10

The minus (-)ends of microtubules are often anchored at the ________________ ,such that the dynamics associated with microtubules is at the plus (+)ends.

Accepted Answer

A) centriole 
B) centrosome 
C) plasma membrane 
D) centromere 
E) mitochondrial outer membrane 
A) centriole 
B) centrosome 
C) plasma membrane 
D) centromere 
E) mitochondrial outer membrane

Question 11

________ are associated with the "pinching in" of the cell membrane during cytokinesis.

Accepted Answer

The answer of ________ are associated with the "pinching in"...

Question 12

All of the following are roles of microfilaments except

Accepted Answer

A) mitotic spindle formation. 
B) muscle cell contraction. 
C) amoeboid movement. 
D) cytoplasmic streaming. 
E) cell migration. 
A) mitotic spindle formation. 
B) muscle cell contraction. 
C) amoeboid movement. 
D) cytoplasmic streaming. 
E) cell migration.

Question 13

According to the current model,which of the following is the correct sequence of microtubule assembly?

Accepted Answer

A) dimers, oligomers, sheets of protofilaments, protofilaments, closing of microtubule, elongating microtubule 
B) dimers, sheets of protofilaments, closing of microtubule, oligomers, protofilaments, elongating microtubule 
C) dimers, oligomers, protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule 
D) protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule, dimers, oligomers 
E) dimers, oligomers, protofilaments, elongating microtubule, sheets of protofilaments, closing of microtubule 
A) dimers, oligomers, sheets of protofilaments, protofilaments, closing of microtubule, elongating microtubule 
B) dimers, sheets of protofilaments, closing of microtubule, oligomers, protofilaments, elongating microtubule 
C) dimers, oligomers, protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule 
D) protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule, dimers, oligomers 
E) dimers, oligomers, protofilaments, elongating microtubule, sheets of protofilaments, closing of microtubule

Question 14

Capping proteins such as CapZ

Accepted Answer

A) cause microtubules to lengthen. 
B) destabilize microtubules. 
C) stabilize microtubules. 
D) cause microtubules branching. 
E) connect microtubules to microfilaments. 
A) cause microtubules to lengthen. 
B) destabilize microtubules. 
C) stabilize microtubules. 
D) cause microtubules branching. 
E) connect microtubules to microfilaments.

Question 15

Activation of the ________ G-protein results in the extension of lamellipodia.

Accepted Answer

The answer of Activation of the ________ G-protein results in...

Question 16

Many drugs have the ability to disrupt the cytoskeletal structure of the cell.These drugs are useful in the study of microtubules and microfilaments.
a. What are some of the drugs used to study microfilaments?
b. What are some of the drugs used to study microtubules?
c. What additional technique with applications similar to these drugs is often used to study the cytoskeleton?
d. Cancer is a disease in which cells divide uncontrollably.Many of the drugs used in the study of microtubules are also used in the treatment of cancer.From what you know about microtubules and microfilaments,can you suggest why drugs that disrupt microtubules are more useful in the treatment of cancer than drugs used to disrupt microfilaments?
e. These anticancer drugs are in a category of drugs that describes their function.What is the category?

Accepted Answer

a. cytochalasin D,latrunculin A,phalloid

Question 17

Match between columns
                        Premises: axonemal microtubules

Accepted Answer

The Answer of nucleating actin branches and account for 10-15% is...

Question 18

Choose the item that best matches the other items.
-nonmotor 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 19

The ________ is a complex network of interconnected filaments and tubules that extends throughout the cytosol,from the nucleus to the inner surface of the plasma membrane.

Accepted Answer

A) cytoskeleton 
B) microtubule apparatus 
C) cell scaffold 
D) desmin sheath 
E) microfilament array 
A) cytoskeleton 
B) microtubule apparatus 
C) cell scaffold 
D) desmin sheath 
E) microfilament array

Question 20

Which of the following proteins is associated with the precise control of where microtubules form and depolymerize?

Accepted Answer

A) Tau 
B) stathmin/Op18 
C) kinesin 
D) catastrophins 
E) MAP 2 
A) Tau 
B) stathmin/Op18 
C) kinesin 
D) catastrophins 
E) MAP 2

Exam 15: Cytoskeletal Systems

Elongation of the microtubule occurs by the

Microfilaments function in

Actin bundles give shape and support to the ________ found in cells of the small intestine.

In binary fission,one would expect the involvement of which of the following cytoskeletal proteins?

Choose the item that best matches the other items. -capping protein

Based upon your knowledge of the cytoskeleton,explain how the discovery of cytoskeletal elements in prokaryotes contributed to the current understanding of the endosymbiont theory.

Activation of the ________ G-protein results in the formation of focal adhesions and stress fibers.

The ________ model is used to describe the simultaneous polymerization and depolymerization of microtubules.

The minus (-)ends of microtubules are often anchored at the ________________ ,such that the dynamics associated with microtubules is at the plus (+)ends.

________ are associated with the "pinching in" of the cell membrane during cytokinesis.

All of the following are roles of microfilaments except

According to the current model,which of the following is the correct sequence of microtubule assembly?

Capping proteins such as CapZ

Activation of the ________ G-protein results in the extension of lamellipodia.

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

The ________ is a complex network of interconnected filaments and tubules that extends throughout the cytosol,from the nucleus to the inner surface of the plasma membrane.

Which of the following proteins is associated with the precise control of where microtubules form and depolymerize?

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

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