Question 1

Intermediate filaments

Accepted Answer

A)  lack the intrinsic polarity of microtubules and microfilaments,because IF tetrameric subunits are symmetric.
B)  are grouped into five cytoplasmic classes based on the cell types in which they are found and one nuclear class.
C)  are the most stable and least soluble cytoskeleton filaments.
D)  are not found in plant cell cytoplasm.
E)  All of the above are true.

Question 2

Explain how the discovery of cytoskeletal elements in prokaryotes contributed to the current understanding of the endosymbiont theory.

Accepted Answer

The tubulin-like protein FtsZ is involve...

Question 3

Which of the following is true about the structure of the microtubule wall?

Accepted Answer

A)  α-β-tubulin heterodimers are arranged with mixed orientation in each protofilament,and protofilaments are arranged with mixed polarity in the microtubule wall.
B)  α-β-tubulin heterodimers are arranged with the same orientation in each protofilament,and protofilaments are arranged with mixed polarity in the microtubule wall.
C)  α-β-tubulin heterodimers are arranged with the mixed orientation in each protofilament,and protofilaments are arranged with same polarity in the microtubule wall.
D)  α-β-tubulin heterodimers are arranged with the same orientation in each protofilament,and protofilaments are arranged with same polarity in the microtubule wall.
E)  Orientation of the α-β-tubulin heterodimers is completely random and depends on which end of the dimer first hits the end of the microtubule when it assembles.

Question 4

Cancer cells retain the IF proteins from the tissue of origin even after metastasizing to other tissues.How is this important in the diagnosis and treatment of cancer?

Accepted Answer

Evidence for metastasis (movement of can...

Question 5

A network of ________,a "fourth cytoskeleton" is involved in pinching off yeast daughter cells.

Accepted Answer

The answer of A network of ________,a "fourth cytoskeleton" is...

Question 6

A microtubule-organizing center (MTOC)

Accepted Answer

A)  contains centrioles in plant cells.
B)  serves as a site for both microtubule and intermediate filament assembly.
C)  anchors either end of cytoplasmic microtubules.
D)  anchors only the minus ends of cytoplasmic microtubules.
E)  usually is positioned near the cell membrane. D

Question 7

The Mitchison and Kirschner ________ model of how microtubules transition between periods of growth and catastrophe proposes that ________ bound to β-tubulin subunits at a microtubule plus end stabilizes the end and promotes growth,but if the rate of hydrolysis to ________ exceeds the rate of tubulin addition,the end becomes unstable and loses subunits.

Accepted Answer

dynamic in...

Question 8

All of the following are components associated with bacterial cytoskeletons except

Accepted Answer

A)  FtsZ.
B)  MreB.
C)  plectin.
D)  crescentin.
E)  A,B,C,and D are associated with the bacterial cytoskeletons.

Question 9

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

Accepted Answer

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

Question 10

________ is a drug that blocks cell division by stabilizing microtubules; as a result,it is used in the treatment of ________.

Accepted Answer

A)  Vincristine; listeriosis
B)  Vinblastine; lung cancer
C)  Taxol; breast cancer
D)  Nocodazole; athlete's foot
E)  Colchicine; gout

Question 11

A unique feature of ________ is that they are tissue-specific.

Accepted Answer

intermedia...

Question 12

Microfilaments function in

Accepted Answer

A)  muscle contraction.
B)  cytoplasmic streaming.
C)  cell division.
D)  maintenance of animal cell shape.
E)  All of the above.

Question 13

Which of the following proteins is associated with the precise control of where microtubules depolymerize during mitosis?

Accepted Answer

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

Question 14

Actin filaments may form each of the following except

Accepted Answer

A)  3D filament networks (gels) .
B)  contractile bundles.
C)  branched networks.
D)  bundles of parallel filaments.
E)  axonemes containing doublet microfilaments.

Question 15

What are some of the drugs used to study microtubules?

Accepted Answer

colchicine,vincristi...

Question 16

Which of the following microtubule-interacting proteins would you target to disrupt cell division in actively replicating tumor cells?

Accepted Answer

A)  Tau
B)  EB1 (a +-TIP protein) 
C)  MCAK (a catastrophin) 
D)  plectin (a spectraplakin) 
E)  MAP2

Question 17

Cancer is a disease in which cells exhibit uncontrolled cell division.Drugs used in the study of microtubules are also used in the treatment of cancer.Why are drugs that disrupt microtubules more useful in the treatment of cancer than are drugs used to disrupt microfilaments? What is the name of the category of these drugs that describes their function?

Accepted Answer

Microtubules,especially those in the mitotic spindle,are more important than microfilaments in mitosis.Uncontrolled division of cancer cells depends on the correct functioning of microtubules.Drugs that disrupt the mitotic spindle are categorized as antimitotic drugs.

Question 18

You have discovered a new cytoskeletal element and need to identify and characterize it for further work.How would you go about examining this protein to ultimately classify it as a cytoskeletal element?

Accepted Answer

First,isolate the subunit and determine ...

Question 19

Cytochalasins prevent addition of monomers to preexisting ________.

Accepted Answer

The answer of Cytochalasins prevent addition of monomers to preexisting...

Question 20

CapZ

Accepted Answer

A)  causes microfilaments to lengthen by assembly at their plus ends.
B)  depolymerizes microfilaments at their plus ends.
C)  prevents assembly and disassembly at microfilament plus ends.
D)  forms microfilament branches.
E)  connects microfilaments to microtubules.

Exam 13: Cytoskeletal Systems

Intermediate filaments

Correct Answer
verified

Explain how the discovery of cytoskeletal elements in prokaryotes contributed to the current understanding of the endosymbiont theory.

Correct Answer
verified
The tubulin-like protein FtsZ is involve...
View Answer

Which of the following is true about the structure of the microtubule wall?

Correct Answer
verified

Cancer cells retain the IF proteins from the tissue of origin even after metastasizing to other tissues.How is this important in the diagnosis and treatment of cancer?

Correct Answer
verified
Evidence for metastasis (movement of can...
View Answer

A network of ________,a "fourth cytoskeleton" is involved in pinching off yeast daughter cells.

Correct Answer
verified

A microtubule-organizing center (MTOC)

Correct Answer
verified
D

Correct Answer
verified
dynamic in...
View Answer

All of the following are components associated with bacterial cytoskeletons except

Correct Answer
verified

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

Correct Answer
verified

is a drug that blocks cell division by stabilizing microtubules; as a result,it is used in the treatment of .

Correct Answer
verified

A unique feature of ________ is that they are tissue-specific.

Correct Answer
verified
intermedia...
View Answer

Microfilaments function in

Correct Answer
verified

Which of the following proteins is associated with the precise control of where microtubules depolymerize during mitosis?

Correct Answer
verified
D

Actin filaments may form each of the following except

Correct Answer
verified

What are some of the drugs used to study microtubules?

Correct Answer
verified
colchicine,vincristi...
View Answer

Which of the following microtubule-interacting proteins would you target to disrupt cell division in actively replicating tumor cells?

Correct Answer
verified

Correct Answer
verified
Microtubules,especially those in the mitotic spindle,are more important than microfilaments in mitosis.Uncontrolled division of cancer cells depends on the correct functioning of microtubules.Drugs that disrupt the mitotic spindle are categorized as antimitotic drugs.

You have discovered a new cytoskeletal element and need to identify and characterize it for further work.How would you go about examining this protein to ultimately classify it as a cytoskeletal element?

Correct Answer
verified
First,isolate the subunit and determine ...
View Answer

Cytochalasins prevent addition of monomers to preexisting ________.

Correct Answer
verified

CapZ

Correct Answer
verified

Exam 13: Cytoskeletal Systems

Intermediate filaments

Correct AnswerverifiedShow Answer

Explain how the discovery of cytoskeletal elements in prokaryotes contributed to the current understanding of the endosymbiont theory.

Correct AnswerverifiedThe tubulin-like protein FtsZ is involve...View AnswerShow Answer

Which of the following is true about the structure of the microtubule wall?

Correct AnswerverifiedShow Answer

Cancer cells retain the IF proteins from the tissue of origin even after metastasizing to other tissues.How is this important in the diagnosis and treatment of cancer?

Correct AnswerverifiedEvidence for metastasis (movement of can...View AnswerShow Answer

A network of ________,a "fourth cytoskeleton" is involved in pinching off yeast daughter cells.

Correct AnswerverifiedShow Answer

A microtubule-organizing center (MTOC)

Correct AnswerverifiedD

Correct Answerverifieddynamic in...View AnswerShow Answer

All of the following are components associated with bacterial cytoskeletons except

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

________ is a drug that blocks cell division by stabilizing microtubules; as a result,it is used in the treatment of ________.

Correct AnswerverifiedShow Answer

A unique feature of ________ is that they are tissue-specific.

Correct Answerverifiedintermedia...View AnswerShow Answer

Microfilaments function in

Correct AnswerverifiedShow Answer

Which of the following proteins is associated with the precise control of where microtubules depolymerize during mitosis?

Correct AnswerverifiedD

Actin filaments may form each of the following except

Correct AnswerverifiedShow Answer

What are some of the drugs used to study microtubules?

Correct Answerverifiedcolchicine,vincristi...View AnswerShow Answer

Which of the following microtubule-interacting proteins would you target to disrupt cell division in actively replicating tumor cells?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedMicrotubules,especially those in the mitotic spindle,are more important than microfilaments in mitosis.Uncontrolled division of cancer cells depends on the correct functioning of microtubules.Drugs that disrupt the mitotic spindle are categorized as antimitotic drugs.

You have discovered a new cytoskeletal element and need to identify and characterize it for further work.How would you go about examining this protein to ultimately classify it as a cytoskeletal element?

Correct AnswerverifiedFirst,isolate the subunit and determine ...View AnswerShow Answer

Cytochalasins prevent addition of monomers to preexisting ________.

Correct AnswerverifiedShow Answer

CapZ

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
The tubulin-like protein FtsZ is involve...
View Answer

Correct Answer
verified

Correct Answer
verified
Evidence for metastasis (movement of can...
View Answer

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified
dynamic in...
View Answer

Correct Answer
verified

Correct Answer
verified

is a drug that blocks cell division by stabilizing microtubules; as a result,it is used in the treatment of .

Correct Answer
verified

Correct Answer
verified
intermedia...
View Answer

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
verified
colchicine,vincristi...
View Answer

Correct Answer
verified

Correct Answer
verified
Microtubules,especially those in the mitotic spindle,are more important than microfilaments in mitosis.Uncontrolled division of cancer cells depends on the correct functioning of microtubules.Drugs that disrupt the mitotic spindle are categorized as antimitotic drugs.

Correct Answer
verified
First,isolate the subunit and determine ...
View Answer

Correct Answer
verified

Correct Answer
verified