Question 1

Which of the following is NOT true of the main structural forms of actin?

Accepted Answer

A) Actin filaments form filament bundles. 
B) Actin filaments may form a filament network (gel). 
C) Actin filaments are severed to form filament bundles. 
D) Actin monomers may form actin filaments or G- actin protein complexes. 
E) Capped filaments are made from actin filaments. 
A) Actin filaments form filament bundles. 
B) Actin filaments may form a filament network (gel). 
C) Actin filaments are severed to form filament bundles. 
D) Actin monomers may form actin filaments or G- actin protein complexes. 
E) Capped filaments are made from actin filaments.

Question 2

The is a complex network of interconnected filaments and tubules that extends throughout the cytosol, from the nucleus to the inner surface of the plasma membrane.

Accepted Answer

A) microfilament array 
B) cytoskeleton 
C) cell scaffold 
D) desmin sheath 
E) microtubule apparatus 
A) microfilament array 
B) cytoskeleton 
C) cell scaffold 
D) desmin sheath 
E) microtubule apparatus

Question 3

A high- resolution video camera is used in which of the following microscopic techniques?

Accepted Answer

A) transmission electron microscopy 
B) fluorescent staining of cytoskeleton proteins 
C) scanning electron microscopy 
D) computer- enhanced digital video microscopy 
E) immunofluorescence microscopy 
A) transmission electron microscopy 
B) fluorescent staining of cytoskeleton proteins 
C) scanning electron microscopy 
D) computer- enhanced digital video microscopy 
E) immunofluorescence microscopy

Question 4

F- actin filaments

Accepted Answer

A) are oriented similar to DNA, with strands helical and antiparallel to one another. 
B) are composed of G- actin dimers. 
C) are composed of polymerized G- actin monomers wound around each other in a helix. 
D) polymerize at the same rate in both directions from both ends of the filament. 
E) are composed of four linear strands. 
A) are oriented similar to DNA, with strands helical and antiparallel to one another. 
B) are composed of G- actin dimers. 
C) are composed of polymerized G- actin monomers wound around each other in a helix. 
D) polymerize at the same rate in both directions from both ends of the filament. 
E) are composed of four linear strands.

Question 5

In binary fission, one would expect the involvement of which of the following cytoskeletal proteins?

Accepted Answer

A) FtsZ 
B) tubulin 
C) plaktin 
D) MreB 
E) crescentin 
A) FtsZ 
B) tubulin 
C) plaktin 
D) MreB 
E) crescentin

Question 6

Microtubules and microfilaments differ with respect to each of the following EXCEPT

Accepted Answer

A) occurrence. 
B) size. 
C) associated motor proteins. 
D) subunits. 
E) a state of dynamic instability. 
A) occurrence. 
B) size. 
C) associated motor proteins. 
D) subunits. 
E) a state of dynamic instability.

Question 7

The model is used to describe the simultaneous polymerization and depolymerization of microtubules.

Accepted Answer

The answer of The model is used to describe the...

Question 8

are proteins that promote depolymerization of extant microtubules at the ends.

Accepted Answer

The answer of are proteins that promote depolymerization of extant...

Question 9

Of the following microtubule interacting proteins, which might you potentially investigate as a mechanism for disrupting cell division in actively replicating tumor cells?

Accepted Answer

A) FtsZ 
B) catastrophins 
C) G- actin 
D) tau 
E) +- tip proteins 
A) FtsZ 
B) catastrophins 
C) G- actin 
D) tau 
E) +- tip proteins

Question 10

All of the following are moved by molecular motors EXCEPT

Accepted Answer

A) cytoskeletal filaments. 
B) glucose. 
C) chloroplasts. 
D) secretory vesicles. 
E) Golgi complex. 
A) cytoskeletal filaments. 
B) glucose. 
C) chloroplasts. 
D) secretory vesicles. 
E) Golgi complex.

Question 11

Microfilaments function in

Accepted Answer

A) maintenance of cellular shape in animal cells. 
B) cell division. 
C) cytoplasmic streaming. 
D) muscle contraction. 
E) all of the above 
A) maintenance of cellular shape in animal cells. 
B) cell division. 
C) cytoplasmic streaming. 
D) muscle contraction. 
E) all of the above

Question 12

Based on composition similarities, actin can be divided into two major groups: the muscle- specific actins ( - actin)and nonmuscle actins ( - and
- actin).

Accepted Answer

The answer of Based on composition similarities, actin can be...

Question 13

Critical concentration is

Accepted Answer

A) the concentration of G- actin in most muscle cells. 
B) the concentration of tubulin dimers at which assembly is balanced with disassembly. 
C) required before nucleation can occur. 
D) the concentration of tubulin dimers at which assembly occurs primarily. 
E) both A and D 
A) the concentration of G- actin in most muscle cells. 
B) the concentration of tubulin dimers at which assembly is balanced with disassembly. 
C) required before nucleation can occur. 
D) the concentration of tubulin dimers at which assembly occurs primarily. 
E) both A and D

Question 14

causes microtubules to form tight bundles in nerve cells.

Accepted Answer

A) Tau 
B) Tubulin 
C) Kinesis 
D) Dynein 
E) Actin 
A) Tau 
B) Tubulin 
C) Kinesis 
D) Dynein 
E) Actin

Question 15

Actin bundles give shape and support to the _ found in cells of the small intestine.

Accepted Answer

A) lamellipodia 
B) centrosomes 
C) microvilli 
D) nuclei 
E) microtubules 
A) lamellipodia 
B) centrosomes 
C) microvilli 
D) nuclei 
E) microtubules

Question 16

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

Accepted Answer

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

Question 17

Which of the following is NOT a function associated with the cytoskeleton?

Accepted Answer

A) signal transducer 
B) scaffold for support and maintenance of cell shape 
C) anchoring site for mRNA during transcription 
D) organizes the organelles within the cytoplasm 
E) cell division 
A) signal transducer 
B) scaffold for support and maintenance of cell shape 
C) anchoring site for mRNA during transcription 
D) organizes the organelles within the cytoplasm 
E) cell division

Question 18

According to the current model, which of the following is the correct sequence of microtubule assembly?

Accepted Answer

A) protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule, dimers, oligomers 
B) dimers, oligomers, protofilaments, elongating microtubule, sheets of protofilaments, closing of microtubule 
C) dimers, oligomers, protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule 
D) dimers, sheets of protofilaments, closing of microtubule, oligomers, protofilaments, elongating microtubule 
E) dimers, oligomers, sheets of protofilaments, protofilaments, closing of microtubule, elongating microtubule 
A) protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule, dimers, oligomers 
B) dimers, oligomers, protofilaments, elongating microtubule, sheets of protofilaments, closing of microtubule 
C) dimers, oligomers, protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule 
D) dimers, sheets of protofilaments, closing of microtubule, oligomers, protofilaments, elongating microtubule 
E) dimers, oligomers, sheets of protofilaments, protofilaments, closing of microtubule, elongating microtubule

Exam 15: Cytoskeletal Systems

Which of the following is NOT true of the main structural forms of actin?

The is a complex network of interconnected filaments and tubules that extends throughout the cytosol, from the nucleus to the inner surface of the plasma membrane.

A high- resolution video camera is used in which of the following microscopic techniques?

F- actin filaments

In binary fission, one would expect the involvement of which of the following cytoskeletal proteins?

Microtubules and microfilaments differ with respect to each of the following EXCEPT

The model is used to describe the simultaneous polymerization and depolymerization of microtubules.

are proteins that promote depolymerization of extant microtubules at the ends.

Of the following microtubule interacting proteins, which might you potentially investigate as a mechanism for disrupting cell division in actively replicating tumor cells?

All of the following are moved by molecular motors EXCEPT

Microfilaments function in

Based on composition similarities, actin can be divided into two major groups: the muscle- specific actins ( - actin)and nonmuscle actins ( - and - actin).

Critical concentration is

causes microtubules to form tight bundles in nerve cells.

Actin bundles give shape and support to the _ found in cells of the small intestine.

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

Which of the following is NOT a function associated with the cytoskeleton?

According to the current model, which of the following is the correct sequence of microtubule assembly?

A Preview of the Cell

The Chemistry of the Cell

The Macromolecules of the Cell

Cells and Organelles

Bioenergetics: The Flow of Energy in the Cell

Enzymes: The Catalysts of Life

Membranes: Their Structure, Function, and Chemistry

Transport Across Membranes: Overcoming the Permeability Barrier

Chemotrophic Energy Metabolism: Glycolysis and Fermentation

Chemotrophic Energy Metabolism: Aerobic Respiration

Phototrophic Energy Metabolism: Photosynthesis

The Endomembrane System and Peroxisomes

Signal Transduction Mechanisms: I Electrical and Synaptic Signaling in Neurons

Signal Transduction Mechanisms: Ii Messengers and Receptors

Cellular Movement: Motility and Contractility

Beyond the Cell: Cell Adhesion, Cell Junctions, and Extracellular Structures

The Structural Basis of Cellular Information: DNA, Chromosomes, and the Nucleus

The Cell Cycle, Dna Replication, and Mitosis

Sexual Reproduction, Meiosis, and Genetic Recombination

Gene Expression: I the Genetic Code and Transcription

Gene Expression: II Protein Synthesis and Sorting

The Regulation of Gene Expression

Cancer Cells

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