Question 1

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 2

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

Question 3

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

Question 4

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 
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 5

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. 
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 6

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

Question 7

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. 
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 8

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 
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 9

What is a microtubule protofilament?

Accepted Answer

A microtubule protofilament is

Question 10

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

Question 11

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. 
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.

Question 12

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

Question 13

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

Accepted Answer

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

Question 14

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

Question 15

What are the effects of colchicine and taxol on cells?

Accepted Answer

Colchicine blocks assembly of the cell's

Question 16

MAP2 and Tau are examples of microtubule:

Accepted Answer

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

Question 17

The drug taxol acts to:

Accepted Answer

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

Question 18

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

Question 19

What role do astral microtubules play in spindle elongation?

Accepted Answer

Astral microtubules may serve

Question 20

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

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

What happens to a microtubule that loses its GTP cap?

The alpha and beta tubulin proteins can bind:

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

The primary cilium:

All of the following statements describe kinesin-I EXCEPT:

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

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

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

What is a microtubule protofilament?

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

Which of the following is NOT true about cilia?

Treadmilling through kinetochore microtubules can be observed by:

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

Growing microtubule ends are normally stabilized by:

What are the effects of colchicine and taxol on cells?

MAP2 and Tau are examples of microtubule:

The drug taxol acts to:

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

What role do astral microtubules play in spindle elongation?

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

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Vesicular Traffic, Secretion, and Endocytosis

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Regulating the Eukaryotic Cell Cycle

Integrating Cells Into Tissues

Cell Birth, Lineage, and Death

Nerve Cells

Immunology

Cancer

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