Question 1

What are the effects of colchicine and taxol on cells?

Accepted Answer

Colchicine blocks assembly of the cell's...

Question 2

What happens to a microtubule that loses its GTP cap?

Accepted Answer

Loss of the GTP cap will cause a microtubule to convert from growth to shortening.Shortening will continue until the microtubule disappears or a new cap forms.

Question 3

The region of a motor protein that interacts with the motor's cellular cargo is the:

Accepted Answer

A)  head domain.
B)  tail domain.
C)  rod domain.
D)  light chains.

Question 4

What role do astral microtubules play in spindle elongation?

Accepted Answer

Astral microtubules may serve ...

Question 5

The _____ serves as a template for the unusual structure of axoneme microtubules.

Accepted Answer

A)  γ-tubulin ring complex
B)  pericentriolar material
C)  centrosome
D)  basal body

Question 6

The drug taxol acts to:

Accepted Answer

A)  block microtubule assembly.
B)  stabilize microtubules against depolymerization.
C)  promote cell division.
D)  sever microtubules.

Question 7

The alpha and beta tubulin proteins can bind:

Accepted Answer

A)  to ATP or ADP.
B)  to GTP or GDP.
C)  only to GDP.
D)  none of the above D

Question 8

The important role that intermediate filaments play in the epithelial cells of the skin is evident in which of the following?

Accepted Answer

A)  Individual keratin filaments span the cell membrane and directly connect one cell to the next.
B)  Knockout mice for a keratin gene like K14 exhibit stronger skin that can withstand abrasion.
C)  The polarity of keratin filaments allows them to withstand shear stress.
D)  Patients with mutations in keratin genes exhibit skin problems.

Question 9

All of the following statements describe kinesin-I EXCEPT:

Accepted Answer

A)  kinesin-I is a (−) end-directed motor.
B)  kinesin-I transports vesicles along microtubules.
C)  kinesin-I binds and hydrolyzes ATP to produce movement.
D)  kinesin-I is composed of two heavy chains and two light chains.

Question 10

Growing microtubule ends are normally stabilized by:

Accepted Answer

A)  a GDP cap.
B)  a GTP cap.
C)  phosphorylation of tubulin subunits.
D)  γ-tubulin.

Question 11

A drug that prevents microtubules from depolymerizing could be used to:

Accepted Answer

A)  stimulate cytokinesis.
B)  inhibit mitosis.
C)  promote cell division.
D)  treat Alzheimer's disease.

Question 12

Which of the following is NOT a way in which a microtubule switches from growing to shortening?

Accepted Answer

A)  loss of GTP cap
B)  treatment with colchicine
C)  binding of MAP2
D)  binding of stathmin

Question 13

The primary cilium:

Accepted Answer

A)  is nonmotile because it lacks the "central pair" of microtubules.
B)  is relatively susceptible to microtubule destabilizing drugs like colchicine.
C)  has no known role in humans.
D)  none of the above

Question 14

MAP2 and Tau are examples of microtubule:

Accepted Answer

A)  destabilizing proteins.
B)  motor proteins.
C)  nucleating proteins.
D)  stabilizing proteins.

Question 15

Separation of spindle poles during spindle formation and anaphase B most likely depends on which of the following?

Accepted Answer

A)  (+) end-directed microtubule motors at the cell cortex
B)  (+) end-directed microtubule motors at the kinetochore
C)  (−) end-directed microtubule motors in the microtubule overlap zone
D)  (+) end-directed microtubule motors in the microtubule overlap zone

Question 16

For kinesin motors,the direction of movement along a microtubule is specified by the motor's:

Accepted Answer

A)  motor (head) domain.
B)  neck region.
C)  stalk domain.
D)  tail domain. B

Question 17

What is a microtubule protofilament?

Accepted Answer

A microtubule protofilament is...

Question 18

Which of the following does NOT belong to the intermediate filament protein family?

Accepted Answer

A)  vimentin
B)  keratin
C)  laminin
D)  desmin

Question 19

Treadmilling through kinetochore microtubules can be observed by:

Accepted Answer

A)  simple fluorescence microscopy.
B)  optical trap microscopy.
C)  fluorescence speckle microscopy.
D)  electron microscopy.

Question 20

Which of the following is NOT true about cilia?

Accepted Answer

A)  All cilia arise from nine sets of outer triplet microtubules (similar to centrioles) .
B)  Cilia contain the same transport system as flagella,called IFT.
C)  All cells with cilia are motile because of the axonemal dynein motor.
D)  Primary cilia contain receptors that increase the cell's responsiveness to its environment.

Exam 17: Cell Organization and Movement II: Microtubules and Intermediate Filaments

What are the effects of colchicine and taxol on cells?

Correct AnswerverifiedColchicine blocks assembly of the cell's...View AnswerShow Answer

What happens to a microtubule that loses its GTP cap?

Correct AnswerverifiedLoss of the GTP cap will cause a microtubule to convert from growth to shortening.Shortening will continue until the microtubule disappears or a new cap forms.

The region of a motor protein that interacts with the motor's cellular cargo is the:

Correct AnswerverifiedShow Answer

What role do astral microtubules play in spindle elongation?

Correct AnswerverifiedAstral microtubules may serve ...View AnswerShow Answer

The _____ serves as a template for the unusual structure of axoneme microtubules.

Correct AnswerverifiedShow Answer

The drug taxol acts to:

Correct AnswerverifiedShow Answer

The alpha and beta tubulin proteins can bind:

Correct AnswerverifiedD

The important role that intermediate filaments play in the epithelial cells of the skin is evident in which of the following?

Correct AnswerverifiedShow Answer

All of the following statements describe kinesin-I EXCEPT:

Correct AnswerverifiedShow Answer

Growing microtubule ends are normally stabilized by:

Correct AnswerverifiedShow Answer

A drug that prevents microtubules from depolymerizing could be used to:

Correct AnswerverifiedShow Answer

Which of the following is NOT a way in which a microtubule switches from growing to shortening?

Correct AnswerverifiedShow Answer

The primary cilium:

Correct AnswerverifiedShow Answer

MAP2 and Tau are examples of microtubule:

Correct AnswerverifiedShow Answer

Separation of spindle poles during spindle formation and anaphase B most likely depends on which of the following?

Correct AnswerverifiedShow Answer

For kinesin motors,the direction of movement along a microtubule is specified by the motor's:

Correct AnswerverifiedB

What is a microtubule protofilament?

Correct AnswerverifiedA microtubule protofilament is...View AnswerShow Answer

Which of the following does NOT belong to the intermediate filament protein family?

Correct AnswerverifiedShow Answer

Treadmilling through kinetochore microtubules can be observed by:

Correct AnswerverifiedShow Answer

Which of the following is NOT true about cilia?

Correct AnswerverifiedShow Answer

Correct Answer
verified
Colchicine blocks assembly of the cell's...
View Answer

Correct Answer
verified
Loss of the GTP cap will cause a microtubule to convert from growth to shortening.Shortening will continue until the microtubule disappears or a new cap forms.

Correct Answer
verified

Correct Answer
verified
Astral microtubules may serve ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified
A microtubule protofilament is...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified