Question 1

In the axoneme,nexin

Accepted Answer

A) transports tubulin to the axoneme tip for assembly. 
B) generates force for outer doublets sliding past each other. 
C) projects inward from each doublet toward the central pair microtubules. 
D) links adjacent outer doublets to limit sliding. 
E) connects each outer doublet to the plasma membrane. 
A) transports tubulin to the axoneme tip for assembly. 
B) generates force for outer doublets sliding past each other. 
C) projects inward from each doublet toward the central pair microtubules. 
D) links adjacent outer doublets to limit sliding. 
E) connects each outer doublet to the plasma membrane.

Question 2

Which of the following proteins attaches a crawling cell to the substrate in a focal adhesion?

Accepted Answer

A) actin 
B) myosins 
C) α-actinin 
D) integrin 
E) titin 
A) actin 
B) myosins 
C) α-actinin 
D) integrin 
E) titin

Question 3

The ________ element of the sarcoplasmic reticulum is where ________ function to decrease sarcoplasmic Ca2+ concentration for muscle relaxation.

Accepted Answer

Question 4

Each of the following diseases is classified as a primary cilia dysplasia (also known as a ciliopathy)except

Accepted Answer

A) Kartagener's syndrome. 
B) situs inversus totalis. 
C) heterotaxia. 
D) Griscelli's disease. 
E) All are primary cilia dysplasias. 
A) Kartagener's syndrome. 
B) situs inversus totalis. 
C) heterotaxia. 
D) Griscelli's disease. 
E) All are primary cilia dysplasias.

Question 5

Where would you expect to find the Ca2+-activated form of gelsolin in cells crawling by amoeboid movement?

Accepted Answer

A) in and around focal adhesions 
B) at a pseudopodium tip where endoplasm is converting to ectoplasm 
C) at a pseudopodium base where ectoplasm is converting to endoplasm 
D) in the primary cilium 
E) at the cell trailing edge where force is produced to drive endoplasm forward streaming 
A) in and around focal adhesions 
B) at a pseudopodium tip where endoplasm is converting to ectoplasm 
C) at a pseudopodium base where ectoplasm is converting to endoplasm 
D) in the primary cilium 
E) at the cell trailing edge where force is produced to drive endoplasm forward streaming

Question 6

Which of the following is incorrect about stimulation of striated muscle contraction by the neuromuscular junction?

Accepted Answer

A) Acetylcholine is stored in vesicles in the axon terminal. 
B) Acetylcholine is secreted in response to a nerve action potential. 
C) Acetylcholine binds to soluble receptors in the extracellular environment. 
D) Acetylcholine binding stimulates sodium ions to enter the muscle cell. 
E) T tubules carry action potentials into the muscle cell. 
A) Acetylcholine is stored in vesicles in the axon terminal. 
B) Acetylcholine is secreted in response to a nerve action potential. 
C) Acetylcholine binds to soluble receptors in the extracellular environment. 
D) Acetylcholine binding stimulates sodium ions to enter the muscle cell. 
E) T tubules carry action potentials into the muscle cell.

Question 7

Striated muscle has light and dark bands.The light bands are called ________,whereas the dark bands are called ________.

Accepted Answer

A) Z lines; M lines 
B) H zones; M zones 
C) A bands; I bands 
D) I bands; A bands 
E) M lines; A bands 
A) Z lines; M lines 
B) H zones; M zones 
C) A bands; I bands 
D) I bands; A bands 
E) M lines; A bands

Question 8

Ca2+-calmodulin stimulates phosphorylation of myosin by

Accepted Answer

A) Ca2+-ATPase. 
B) focal adhesion kinase. 
C) myosin light chain kinase. 
D) ryanodine receptor. 
E) titin. 
A) Ca2+-ATPase. 
B) focal adhesion kinase. 
C) myosin light chain kinase. 
D) ryanodine receptor. 
E) titin.

Question 9

Which of the following statements is correct with respect to flagella and cilia?

Accepted Answer

A) The flagellum is usually at the leading end of a swimming sperm cell. 
B) Cilia generate a force parallel to the cell surface. 
C) There usually are fewer cilia than flagella. 
D) Cilia generally are longer than flagella. 
E) Cilia often have a helical pattern of movement. 
A) The flagellum is usually at the leading end of a swimming sperm cell. 
B) Cilia generate a force parallel to the cell surface. 
C) There usually are fewer cilia than flagella. 
D) Cilia generally are longer than flagella. 
E) Cilia often have a helical pattern of movement.

Question 10

In the axoneme,sidearms

Accepted Answer

A) are 10 protofilament incomplete microtubules attached to 13 protofilament microtubules. 
B) generate force to slide microtubules past one another. 
C) project toward the central pair from each outer doublet. 
D) link adjacent doublet microtubules to limit sliding. 
E) are complete 13 protofilament microtubules. 
A) are 10 protofilament incomplete microtubules attached to 13 protofilament microtubules. 
B) generate force to slide microtubules past one another. 
C) project toward the central pair from each outer doublet. 
D) link adjacent doublet microtubules to limit sliding. 
E) are complete 13 protofilament microtubules.

Question 11

Consider the observations that a label on one head of a myosin V dimer moves in steps of 72 nm,but a label much nearer the myosin tail moves in steps of 36 nm.Discuss how these observations support a hand-over-hand mechanism rather than an inchworm mechanism of myosin V motility on an actin filament.

Accepted Answer

In the inchworm model,each myosin head w

Question 12

In the sliding filament model of muscle contraction,I bands contain

Accepted Answer

A) thick filaments. 
B) thin filaments. 
C) myosin II. 
D) myomesin. 
E) both thick and thin filaments. 
A) thick filaments. 
B) thin filaments. 
C) myosin II. 
D) myomesin. 
E) both thick and thin filaments.

Question 13

Biochemical evidence supporting the sliding filament model of muscle contraction includes the observation that

Accepted Answer

A) myosin light chains can be phosphorylated. 
B) titin connects each end of a thick filament to a Z line. 
C) TnC binds Ca2+. 
D) actin has polymerization ATPase activity. 
E) myosin has an ATP-dependent crossbridge cycle. 
A) myosin light chains can be phosphorylated. 
B) titin connects each end of a thick filament to a Z line. 
C) TnC binds Ca2+. 
D) actin has polymerization ATPase activity. 
E) myosin has an ATP-dependent crossbridge cycle.

Question 14

When migrating cells move toward a greater concentration of a diffusible chemical,the chemical is called a ________.

Accepted Answer

The answer of When migrating cells move toward a greater...

Question 15

Which of the following sequences is in the correct order for the cyclic process by which a myosin head generates force on an actin filament for muscle contraction?

Accepted Answer

A) power stroke,crossbridge formation,crossbridge dissociation,cocking of myosin head 
B) crossbridge formation,power stroke,crossbridge dissociation,cocking of myosin head 
C) crossbridge formation,cocking of myosin head,power stroke,crossbridge dissociation 
D) crossbridge formation,crossbridge dissociation,cocking of myosin head,power stroke 
E) crossbridge formation,power stroke,crossbridge dissociation,power stroke,cocking of myosin head 
A) power stroke,crossbridge formation,crossbridge dissociation,cocking of myosin head 
B) crossbridge formation,power stroke,crossbridge dissociation,cocking of myosin head 
C) crossbridge formation,cocking of myosin head,power stroke,crossbridge dissociation 
D) crossbridge formation,crossbridge dissociation,cocking of myosin head,power stroke 
E) crossbridge formation,power stroke,crossbridge dissociation,power stroke,cocking of myosin head

Question 16

The axonemal "9 + 2" pattern of microtubules is nine ________ surrounding a(n)________.

Accepted Answer

A) outer doublets; central pair 
B) basal bodies; inner two 
C) central tubules; double pair 
D) B tubule structures; middle two 
E) triplet microtubules; basal bodies 
A) outer doublets; central pair 
B) basal bodies; inner two 
C) central tubules; double pair 
D) B tubule structures; middle two 
E) triplet microtubules; basal bodies

Question 17

Which of the following features is not shared by microtubule and microfilament molecular motors?

Accepted Answer

A) coupling ATP hydrolysis to change shape and attachment of the motor to its associated cytoskeletal filament 
B) retention of bound ADP and Pi products immediately after ATP hydrolysis 
C) cycles of ATP hydrolysis,release of ADP and Pi,and binding of new ATP as they undergo a crossbridge cycle of force production on a filament 
D) similar structural features that transduce changes in the motor protein shape into movement 
E) The motors share all these features. 
A) coupling ATP hydrolysis to change shape and attachment of the motor to its associated cytoskeletal filament 
B) retention of bound ADP and Pi products immediately after ATP hydrolysis 
C) cycles of ATP hydrolysis,release of ADP and Pi,and binding of new ATP as they undergo a crossbridge cycle of force production on a filament 
D) similar structural features that transduce changes in the motor protein shape into movement 
E) The motors share all these features.

Question 18

Motility may involve

Accepted Answer

A) movement of a cell/organism through its environment. 
B) movement of the environment past a cell. 
C) movement of components within a cell. 
D) shortening of a cell. 
E) All of the above are correct. 
A) movement of a cell/organism through its environment. 
B) movement of the environment past a cell. 
C) movement of components within a cell. 
D) shortening of a cell. 
E) All of the above are correct.

Question 19

Which of the following is responsible for retrograde axonal transport?

Accepted Answer

A) cytoplasmic dynein 
B) kinesin 5 
C) kinesin 13 
D) myosin V 
E) kinesin 1 
A) cytoplasmic dynein 
B) kinesin 5 
C) kinesin 13 
D) myosin V 
E) kinesin 1

Question 20

Kinesin 1 and myosin II share each of the following features except

Accepted Answer

A) two heads. 
B) dimers formed by heavy chain tails coiled around each other. 
C) formation of bipolar filaments. 
D) plus end directed motor activity. 
E) ATPase activity. 
A) two heads. 
B) dimers formed by heavy chain tails coiled around each other. 
C) formation of bipolar filaments. 
D) plus end directed motor activity. 
E) ATPase activity.

Exam 14: Cellular Movement: Motility and Contractility

In the axoneme,nexin

Which of the following proteins attaches a crawling cell to the substrate in a focal adhesion?

The ________ element of the sarcoplasmic reticulum is where ________ function to decrease sarcoplasmic Ca2+ concentration for muscle relaxation.

Each of the following diseases is classified as a primary cilia dysplasia (also known as a ciliopathy)except

Where would you expect to find the Ca2+-activated form of gelsolin in cells crawling by amoeboid movement?

Which of the following is incorrect about stimulation of striated muscle contraction by the neuromuscular junction?

Striated muscle has light and dark bands.The light bands are called ________,whereas the dark bands are called ________.

Ca2+-calmodulin stimulates phosphorylation of myosin by

Which of the following statements is correct with respect to flagella and cilia?

In the axoneme,sidearms

In the sliding filament model of muscle contraction,I bands contain

Biochemical evidence supporting the sliding filament model of muscle contraction includes the observation that

When migrating cells move toward a greater concentration of a diffusible chemical,the chemical is called a ________.

Which of the following sequences is in the correct order for the cyclic process by which a myosin head generates force on an actin filament for muscle contraction?

The axonemal "9 + 2" pattern of microtubules is nine ________ surrounding a(n)________.

Which of the following features is not shared by microtubule and microfilament molecular motors?

Motility may involve

Which of the following is responsible for retrograde axonal transport?

Kinesin 1 and myosin II share each of the following features except

A Preview of Cell Biology

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

Cytoskeletal Systems

Beyond the Cell: Cell Adhesions, cell Junctions, and Extracellular Structures

The Structural Basis of Cellular Information: Dna, chromosomes, and the Nucleus

DNA Replication, repair, and Recombination

Gene Expression: Ithe Genetic Code and Transcription

Gene Expression: Iiprotein Synthesis and Sorting

The Regulation of Gene Expression

Molecular Biology Techniques for Cell Biology

Signal Transduction Mechanisms: Ielectrical and Synaptic Signaling in Neurons

Signal Transduction Mechanisms: Iimessengers and Receptors

The Cell Cycle and Mitosis

Sexual Reproduction,meiosis,and Genetic Recombination

Filters

The element of the sarcoplasmic reticulum is where function to decrease sarcoplasmic Ca2⁺ concentration for muscle relaxation.

Where would you expect to find the Ca2⁺-activated form of gelsolin in cells crawling by amoeboid movement?

Striated muscle has light and dark bands.The light bands are called ,whereas the dark bands are called .

Ca2⁺-calmodulin stimulates phosphorylation of myosin by

The axonemal "9 + 2" pattern of microtubules is nine surrounding a(n).