Question 1

It was found that Listeria infection could not be spread from one cell to its neighbors on a petri dish in the presence of cytochalasin. This suggested that ___________.

Accepted Answer

A)  actin polymerization is required for Listeria infection
B)  tubulin polymerization is required for Listeria infection
C)  cytochalasin is required for Listeria infection
D)  cytochalasin is toxic
E)  intermediate filaments are required for Listeria infectionF) B) and D)
G) A) and D)

Question 2

With which of the following structures are intermediate filaments associated?

Accepted Answer

A)  the nuclear envelope in the center of the cell
B)  hemidesmosomes
C)  desmosomes
D)  theneurofilaments of neuronal axons
E)  all of these choices are correctF) B) and D)
G) C) and D) E

Question 3

What kinds of forces hold microtubular structure together?

Accepted Answer

A)  strong interactions
B)  noncovalent interactions
C)  covalent interactions
D)  magnetism
E)  strong interactions and covalent interactionsF) None of the above
G) D) and E)

Question 4

In a normal microtubule, how many protofilaments make up its cylindrical wall?

Accepted Answer

A)  13
B)  15
C)  11
D)  9
E)  17F) A) and C)
G) A) and B)

Question 5

Which of the following is most extensible?

Accepted Answer

A)  intermediate filaments
B)  microtubules
C)  actin filaments
D)  spindle fibers
E)  microtubules and spindle fibersF) A) and B)
G) B) and C)

Question 6

Which region of the sarcomere represents the region of overlap between the two types of filaments in the sarcomere?

Accepted Answer

A)  A bands
B)  the part of the A band on either side of the H zone
C)  I bands
D)  Z lines
E)  the part of the H zone on either side of the A bandF) B) and C)
G) None of the above

Question 7

How do muscle cells become multinucleate?

Accepted Answer

A)  They become multinucleate as they undergo fission.
B)  They become multinucleate via the embryonic fusion of large numbers of mononucleate myoblasts.
C)  They become multinucleate via the embryonic fusion of large numbers of multinucleate myoblasts.
D)  They become multinucleate via mitosis in myoblasts without cytokinesis.
E)  They become multinucleate via the embryonic fusion of mononucleaateneuroblasts.F) A) and B)
G) A) and C)

Question 8

The role of building the cytokinetic ring during cell division in prokaryotes is executed by _________.

Accepted Answer

A)  actin
B)  tubulin
C)  FtsZ
D)  ParM
E)  CrescentinF) B) and C)
G) A) and B)

Question 9

What motor is associated with microfilaments?

Accepted Answer

A)  myoglobin
B)  kinesin
C)  myosin
D)  dynein
E)  myometriumF) A) and D)
G) A) and E) C

Question 10

Why is myosin V able to take very large steps along a microfilament?

Accepted Answer

A)  Its neck is twisted.
B)  Its neck is relatively long.
C)  Its neck is relatively short.
D)  Its tail is very long.
E)  Its tail is bipolar.F) B) and D)
G) A) and E)

Question 11

The central, rod-shaped domain of an intermediate filament is flanked on each side by globular domains of variable size and sequence. What structure forms the core of the central, rod-shaped domain?

Accepted Answer

A)  alpha-helix
B)  beta-pleated sheet
C)  double helix
D)  quaternary coil
E)  coiled coilF) A) and D)
G) All of the above

Question 12

The peripheral doublets of the axoneme are connected to one another by a(n) ________ composed of an elastic protein-based linkage called the _______.

Accepted Answer

A)  intersheath bridge, nexin link
B)  peridoublet sheath, dynein link
C)  interdoublet bridge, nexin link
D)  interdoublet sheath, dynein link
E)  peridoublet sheath, nexin linkF) B) and C)
G) A) and D)

Question 13

Using a macrophage‐like cell line, researchers infected one set of petri dishes with wild‐type Listeria, and, as anegative control, infected another set with a Listeria mutant that was unable to enter cells. At specific time points, the cells were fixed and prepared for electron microscopy. Two hours after infection, they observed that the wild‐type Listeria in the cytoplasmwere surrounded by ______________.

Accepted Answer

A)  a cloud of tubulin
B)  a cloud of actin
C)  a cloud of keratin
D)  agrowth cone
E)  comet tails of actin filamentsF) None of the above
G) A) and E)

Question 14

________ proteins share considerable sequence homology with actins and accelerate the polymerization of actin filaments.

Accepted Answer

A)  Actin-nucleating
B)  Actin-racemase
C)  Actin-related
D)  Tubulin-related
E)  Actin-ratedF) B) and E)
G) None of the above C

Question 15

Left or right handed spiral growth in Arabidopsis has been linked to all of the following proteins EXCEPT:

Accepted Answer

A)  α tubulin
B)  β tubulin
C)  plant specific MAPs
D)  actin
E)  all of these proteins have been linked to spiral growthF) A) and B)
G) C) and D)

Question 16

What seems to control the assembly and disassembly of intermediate filaments?

Accepted Answer

A)  denaturation
B)  sulfation
C)  phosphorylation and dephosphorylation
D)  hydrolysis
E)  hydroxylationF) A) and B)
G) A) and E)

Question 17

Which of the following is normally associated with the cilia of organisms from protists to mammals?

Accepted Answer

A)  a 9 + 0 pattern
B)  a 9 + 1 pattern
C)  a 9 + 2 pattern
D)  a 9 + 3 pattern
E)  none of these choicesF) B) and D)
G) A) and E)

Question 18

What is the direct source of energy that powers molecular motors?

Accepted Answer

A)  hydrolysis of GTP
B)  hydrolysis of ATP
C)  aproton gradient
D)  an H+ gradient
E)  condensation of ATPF) None of the above
G) C) and E)

Question 19

Myofibrils in a muscle cell are made up of a repeating linear array of contractile units called ________.

Accepted Answer

A)  sarcocytes
B)  blastomeres
C)  myomeres
D)  sarcomeres
E)  myotubulesF) C) and D)
G) B) and E)

Question 20

Which of the following treatments did not help microtubules to polymerize when homogenates prepared from brain tissue received it?

Accepted Answer

A)  Mg2+ ions
B)  GTP
C)  EGTA
D)  a temperature of 37°C
E)  a temperature of 4°CF) C) and D)
G) A) and B)

Exam 9: The Cytoskeleton and Cell Motility

It was found that Listeria infection could not be spread from one cell to its neighbors on a petri dish in the presence of cytochalasin. This suggested that ___________.

Correct Answer
verified

With which of the following structures are intermediate filaments associated?

Correct Answer
verified
E

What kinds of forces hold microtubular structure together?

Correct Answer
verified

In a normal microtubule, how many protofilaments make up its cylindrical wall?

Correct Answer
verified

Which of the following is most extensible?

Correct Answer
verified

Which region of the sarcomere represents the region of overlap between the two types of filaments in the sarcomere?

Correct Answer
verified

How do muscle cells become multinucleate?

Correct Answer
verified

The role of building the cytokinetic ring during cell division in prokaryotes is executed by _________.

Correct Answer
verified

What motor is associated with microfilaments?

Correct Answer
verified
C

Why is myosin V able to take very large steps along a microfilament?

Correct Answer
verified

The central, rod-shaped domain of an intermediate filament is flanked on each side by globular domains of variable size and sequence. What structure forms the core of the central, rod-shaped domain?

Correct Answer
verified

The peripheral doublets of the axoneme are connected to one another by a(n) __ composed of an elastic protein-based linkage called the _.

Correct Answer
verified

Correct Answer
verified

________ proteins share considerable sequence homology with actins and accelerate the polymerization of actin filaments.

Correct Answer
verified
C

Left or right handed spiral growth in Arabidopsis has been linked to all of the following proteins EXCEPT:

Correct Answer
verified

What seems to control the assembly and disassembly of intermediate filaments?

Correct Answer
verified

Which of the following is normally associated with the cilia of organisms from protists to mammals?

Correct Answer
verified

What is the direct source of energy that powers molecular motors?

Correct Answer
verified

Myofibrils in a muscle cell are made up of a repeating linear array of contractile units called ________.

Correct Answer
verified

Which of the following treatments did not help microtubules to polymerize when homogenates prepared from brain tissue received it?

Correct Answer
verified

Exam 9: The Cytoskeleton and Cell Motility

It was found that Listeria infection could not be spread from one cell to its neighbors on a petri dish in the presence of cytochalasin. This suggested that ___________.

Correct AnswerverifiedShow Answer

With which of the following structures are intermediate filaments associated?

Correct AnswerverifiedE

What kinds of forces hold microtubular structure together?

Correct AnswerverifiedShow Answer

In a normal microtubule, how many protofilaments make up its cylindrical wall?

Correct AnswerverifiedShow Answer

Which of the following is most extensible?

Correct AnswerverifiedShow Answer

Which region of the sarcomere represents the region of overlap between the two types of filaments in the sarcomere?

Correct AnswerverifiedShow Answer

How do muscle cells become multinucleate?

Correct AnswerverifiedShow Answer

The role of building the cytokinetic ring during cell division in prokaryotes is executed by _________.

Correct AnswerverifiedShow Answer

What motor is associated with microfilaments?

Correct AnswerverifiedC

Why is myosin V able to take very large steps along a microfilament?

Correct AnswerverifiedShow Answer

The central, rod-shaped domain of an intermediate filament is flanked on each side by globular domains of variable size and sequence. What structure forms the core of the central, rod-shaped domain?

Correct AnswerverifiedShow Answer

The peripheral doublets of the axoneme are connected to one another by a(n) ________ composed of an elastic protein-based linkage called the _______.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

________ proteins share considerable sequence homology with actins and accelerate the polymerization of actin filaments.

Correct AnswerverifiedC

Left or right handed spiral growth in Arabidopsis has been linked to all of the following proteins EXCEPT:

Correct AnswerverifiedShow Answer

What seems to control the assembly and disassembly of intermediate filaments?

Correct AnswerverifiedShow Answer

Which of the following is normally associated with the cilia of organisms from protists to mammals?

Correct AnswerverifiedShow Answer

What is the direct source of energy that powers molecular motors?

Correct AnswerverifiedShow Answer

Myofibrils in a muscle cell are made up of a repeating linear array of contractile units called ________.

Correct AnswerverifiedShow Answer

Which of the following treatments did not help microtubules to polymerize when homogenates prepared from brain tissue received it?

Correct AnswerverifiedShow Answer

Correct Answer
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E

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C

Correct Answer
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Correct Answer
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The peripheral doublets of the axoneme are connected to one another by a(n) __ composed of an elastic protein-based linkage called the _.

Correct Answer
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Correct Answer
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C

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