Question 1

Epidermolysis bullosa simplex is a skin disease caused by a mutation in the gene encoding keratin.

Accepted Answer

A) True 
 B)False  True

Question 2

The kinetic properties of myosin have been optimized such that it moves very rapidly along actin filaments. Specifically, this movement is accomplished by myosin's very brief attachments to the microfilament along which it moves. In contrast, kinesin moves along microtubules more slowly, with longer periods of attachment between each "step." How might these differences be explained in evolutionary terms?

Accepted Answer

Myosin works in conjunction with many other myosin molecules in muscle contraction, and it is unlikely that hundreds of myosin molecules will all let go at once. Therefore, myosin can afford to sacrifice attachment in the interest of speed, which is more adaptive for muscles that need to move quickly for survival. In contrast, vesicles and organelles are moved along a microtubule by just a few molecules of kinesin, so the chances that they could all let go at the same time are higher. Therefore, kinesin takes shorter "steps" along the microtubule with longer attachment periods. This increases the chances that the cargo will make it to its final destination without falling off the microtubule. Transporting the cargo can be a slow and steady process, having relatively little need for speed for survival.

Question 3

Nebulin filaments attach to actin filaments in muscle for what purpose?

Accepted Answer

To organize and stabilize the actin filaments

Question 4

Vimentin is the major intermediate filament protein of _______ cells.

Accepted Answer

A)  epithelial 
B)  striated muscle 
C)  nerve 
D)  fibroblast 
A)  epithelial 
B)  striated muscle 
C)  nerve 
D)  fibroblast

Question 5

Describe the two separate mechanisms by which the poles of the mitotic spindle move apart in anaphase B.

Accepted Answer

Plus-end-directed motor proteins (kinesi

Question 6

Which of the following is not a function of actin-binding proteins?

Accepted Answer

A)  Filament initiation and polymerization 
B)  End capping 
C)  Filament severing/depolymerization 
D)  Incorporation of microfilaments into the extracellular matrix 
A)  Filament initiation and polymerization 
B)  End capping 
C)  Filament severing/depolymerization 
D)  Incorporation of microfilaments into the extracellular matrix

Question 7

Most myosins move along actin filaments toward the _______ end.

Accepted Answer

The answer of Most myosins move along actin filaments toward...

Question 8

Desmosomes are specialized junctions that help hold cells together, while their counterpart hemidesmosomes prevent cell-to-cell contact.

Accepted Answer

A) True 
 B)False

Question 9

In muscle, every myofibril is organized as a chain of contractile units called myocytes.

Accepted Answer

A) True 
 B)False

Question 10

The motor protein that moves cargo toward the minus ends of microtubules is _______.

Accepted Answer

The answer of The motor protein that moves cargo toward...

Question 11

Short actin filaments bind to tetramers of which protein to form the cytoskeleton of erythrocytes?

Accepted Answer

A)  Myosin 
B)  $\alpha$-actinin 
C)  Spectrin 
D)  Ankyrin 
A)  Myosin 
B)  $\alpha$-actinin 
C)  Spectrin 
D)  Ankyrin

Question 12

Adjacent microtubule doublets in cilia and flagella produce a bending movement because

Accepted Answer

A)  tubulin is contracting on one side of the microtubules. 
B)  dynein is contracting on one side of the microtubules. 
C)  kinesin is contracting on one side of the microtubules. 
D)  nexin links between microtubule doublets convert a sliding movement into a bending movement. 
A)  tubulin is contracting on one side of the microtubules. 
B)  dynein is contracting on one side of the microtubules. 
C)  kinesin is contracting on one side of the microtubules. 
D)  nexin links between microtubule doublets convert a sliding movement into a bending movement.

Question 13

Microtubules are assembled from

Accepted Answer

A)  $\alpha$-tubulin dimers. 
B)  $\beta$-tubulin dimers. 
C)  alternating $\alpha$-tubulin dimers and $\beta$-tubulin dimers. 
D)  dimers of $\alpha$- and $\beta$-tubulin. 
A)  $\alpha$-tubulin dimers. 
B)  $\beta$-tubulin dimers. 
C)  alternating $\alpha$-tubulin dimers and $\beta$-tubulin dimers. 
D)  dimers of $\alpha$- and $\beta$-tubulin.

Question 14

The initial role of ATP in the cross-bridge cycle is to bind to _______ and cause it to _______.

Accepted Answer

myosin; re

Question 15

Myosin _______ is present in muscle sarcomeres.

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
A)  I 
B)  II 
C)  III 
D)  IV

Question 16

The role of the centrosome is to

Accepted Answer

A)  determine the center of the cell. 
B)  determine the position of the nucleus. 
C)  initiate microtubule growth. 
D)  adhere to the plus ends of microtubules. 
A)  determine the center of the cell. 
B)  determine the position of the nucleus. 
C)  initiate microtubule growth. 
D)  adhere to the plus ends of microtubules.

Question 17

Describe the myosin II molecule and its component parts.

Accepted Answer

Myosin II is composed of two heavy chain

Question 18

Kinesin and dynein are

Accepted Answer

A)  intermediate filament proteins. 
B)  microtubule motor proteins. 
C)  proteins within centrosomes that mediate nucleation of microtubules. 
D)  microfilament motor proteins. 
A)  intermediate filament proteins. 
B)  microtubule motor proteins. 
C)  proteins within centrosomes that mediate nucleation of microtubules. 
D)  microfilament motor proteins.

Question 19

The GTP bound to $\beta$-tubulin hydrolyzes to GDP and Pi

Accepted Answer

A)  during depolymerization of the $\alpha$-$\beta$ dimer. 
B)  during polymerization of dimers onto microtubules. 
C)  during depolymerization of dimers from microtubules. 
D)  following polymerization but before depolymerization. 
A)  during depolymerization of the $\alpha$-$\beta$ dimer. 
B)  during polymerization of dimers onto microtubules. 
C)  during depolymerization of dimers from microtubules. 
D)  following polymerization but before depolymerization.

Question 20

The anticancer drug taxol

Accepted Answer

A)  blocks microtubule organizing centers. 
B)  stabilizes microtubules and thus inhibits disassembly. 
C)  blocks microtubule assembly by binding to free tubulin. 
D)  accelerates microtubule disassembly by binding to tubulin in microtubules, causing those molecules to exit the microtubule more quickly. 
A)  blocks microtubule organizing centers. 
B)  stabilizes microtubules and thus inhibits disassembly. 
C)  blocks microtubule assembly by binding to free tubulin. 
D)  accelerates microtubule disassembly by binding to tubulin in microtubules, causing those molecules to exit the microtubule more quickly.

Epidermolysis bullosa simplex is a skin disease caused by a mutation in the gene encoding keratin.

Nebulin filaments attach to actin filaments in muscle for what purpose?

Vimentin is the major intermediate filament protein of _______ cells.

Describe the two separate mechanisms by which the poles of the mitotic spindle move apart in anaphase B.

Which of the following is not a function of actin-binding proteins?

Most myosins move along actin filaments toward the _______ end.

Desmosomes are specialized junctions that help hold cells together, while their counterpart hemidesmosomes prevent cell-to-cell contact.

In muscle, every myofibril is organized as a chain of contractile units called myocytes.

The motor protein that moves cargo toward the minus ends of microtubules is _______.

Short actin filaments bind to tetramers of which protein to form the cytoskeleton of erythrocytes?

Adjacent microtubule doublets in cilia and flagella produce a bending movement because

Microtubules are assembled from

The initial role of ATP in the cross-bridge cycle is to bind to _ and cause it to _.

Myosin _______ is present in muscle sarcomeres.

The role of the centrosome is to

Describe the myosin II molecule and its component parts.

Kinesin and dynein are

The GTP bound to $\beta$ -tubulin hydrolyzes to GDP and P_i

The anticancer drug taxol

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

Exam 14: The Cytoskeleton and Cell Movement

Epidermolysis bullosa simplex is a skin disease caused by a mutation in the gene encoding keratin.

Nebulin filaments attach to actin filaments in muscle for what purpose?

Vimentin is the major intermediate filament protein of _______ cells.

Describe the two separate mechanisms by which the poles of the mitotic spindle move apart in anaphase B.

Which of the following is not a function of actin-binding proteins?

Most myosins move along actin filaments toward the _______ end.

Desmosomes are specialized junctions that help hold cells together, while their counterpart hemidesmosomes prevent cell-to-cell contact.

In muscle, every myofibril is organized as a chain of contractile units called myocytes.

The motor protein that moves cargo toward the minus ends of microtubules is _______.

Short actin filaments bind to tetramers of which protein to form the cytoskeleton of erythrocytes?

Adjacent microtubule doublets in cilia and flagella produce a bending movement because

Microtubules are assembled from

The initial role of ATP in the cross-bridge cycle is to bind to _______ and cause it to _______.

Myosin _______ is present in muscle sarcomeres.

The role of the centrosome is to

Describe the myosin II molecule and its component parts.

Kinesin and dynein are

The GTP bound to β\betaβ -tubulin hydrolyzes to GDP and Pi

The anticancer drug taxol

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

The initial role of ATP in the cross-bridge cycle is to bind to _ and cause it to _.

The GTP bound to $\beta$ -tubulin hydrolyzes to GDP and P_i