Cell Biology

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

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

Microtubules and microfilaments differ with respect to each of the following except 
A) size. 
B) occurrence. 
C) associated motor proteins. 
D) a state of dynamic instability. 
E) subunits.

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Activation of which of the following is associated with the formation of focal adhesions and stress

Activation of which of the following is associated with the formation of focal adhesions and stress

Activation of which of the following is associated with the formation of focal adhesions and stress fibers? 
A) Rho 
B) Ras 
C) Cdk-42 
D) intermediate filaments 
E) γ-tubulin

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

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

Which of the following is not true of the main structural forms of actin? 
A) Actin filaments may form a filament network (gel).   
B) Actin monomers may form actin filaments or G-actin protein complexes. 
C) Actin fil

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Of the following proteins, which would be a good target for drug therapy if one needed to interfere

Of the following proteins, which would be a good target for drug therapy if one needed to interfere

Of the following proteins, which would be a good target for drug therapy if one needed to interfere with breaking down the microfilament network?
A) profilin
B) CapZ
C) gelsolin
D) tropomodulin
E) calmodulin

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Intermediate filaments (Multiple Choice)

Intermediate filaments (Multiple Choice)

Intermediate filaments 
A) were first discovered in muscle cells. 
B) are grouped into five classes based on the cell types in which they are found.   
C) have molecular masses averaging 500 kDa. 
D) are smo

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Which stage of microtubule assembly is the stage in which nucleation occurs?

Which stage of microtubule assembly is the stage in which nucleation occurs?

Which stage of microtubule assembly is the stage in which nucleation occurs? 
A) sheets of protofilaments   
B) closing of microtubules 
C) oligomers 
D) dimers 
E) elongation

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

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

According to the current model, which of the following is the correct sequence of microtubule assembly?   
A) dimers, oligomers, sheets of protofilaments, protofilaments, closing of microtubule, elongating microtubule 
B) dimers,

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

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

A high-resolution video camera is used in which of the following microscopic techniques? 
A) immunofluorescence microscopy 
B) fluorescent staining of cytoskeleton proteins 
C) computer-enhanced digital video microsco

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Cytoskeletal elements are found in the

Cytoskeletal elements are found in the

Cytoskeletal elements are found in the
A) Eubacteria.
B) Archaea.
C) Eukarya.
D) choices B and C only
E) all of the above

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Which of the following statements regarding the Ras protein is false?

Which of the following statements regarding the Ras protein is false?

Which of the following statements regarding the Ras protein is false?
A) Ras is monomeric.
B) It is regulated by GTPase activating proteins.
C) The ligands are largely steroid hormones.
D) It is regulated by Sos, a guanine nucleot

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Which of the following is not a plant hormone?

Which of the following is not a plant hormone?

Which of the following is not a plant hormone?
A) brassinosteroids
B) ethylene
C) abscisic acid
D) auxin
E) allomone

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Which of the following are associated with the binding of numerous signaling molecules and regulatin

Which of the following are associated with the binding of numerous signaling molecules and regulatin

Which of the following are associated with the binding of numerous signaling molecules and regulating their responses in multi-enzyme complexes?
A) MAP kinase
B) 14-3-3 proteins
C) growth factor complexes
D) alpha-factor
E)&n

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Which of the following signalling proteins is specifically associated with development in animals?

Which of the following signalling proteins is specifically associated with development in animals?

Which of the following signalling proteins is specifically associated with development in animals?
A) Hedgehog
B) Zbtb7
C) Ryanodine
D) calcium-dependent protein phosphorylases
E) protein kinase A

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A developing organism's failure to produce muscle tissue is most likely due to

A developing organism's failure to produce muscle tissue is most likely due to

A developing organism's failure to produce muscle tissue is most likely due to 
A) underdevelopment of the ectoderm. 
B) underdevelopment of the endoderm. 
C) fibroblast growth factor receptor mutations. 

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In designing a new drug that may interfere with G-protein coupled receptor interacting protein funct

In designing a new drug that may interfere with G-protein coupled receptor interacting protein funct

In designing a new drug that may interfere with G-protein coupled receptor interacting protein functions, one possible target for drug action is not
A) altering ligand affinity for the receptor.
B) promoting close association with other sig

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Which of the following statements is false with regard to G-protein coupled receptors (GPCRs)?

Which of the following statements is false with regard to G-protein coupled receptors (GPCRs)?

Which of the following statements is false with regard to G-protein coupled receptors (GPCRs)?
A) GPCRs can interact with specific receptor interacting proteins to modify ligand affinity.
B) Adenylate cyclase is activated.
C) Phosphodi

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Hyperpolarization of the postsynaptic nerve terminal

Hyperpolarization of the postsynaptic nerve terminal

Hyperpolarization of the postsynaptic nerve terminal
A) decreases the chance that an action potential will be initiated.
B) increases the chance that an action potential will be initiated.
C) does not affect the initiation of an action

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Which of the following statements is false regarding the nicotinic acetylcholine receptor?

Which of the following statements is false regarding the nicotinic acetylcholine receptor?

Which of the following statements is false regarding the nicotinic acetylcholine receptor?
A) The actions of acetylcholine can be mimicked by nicotine.
B) It binds one molecule of acetylcholine for activity.
C) The open channel allows

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The maximum membrane potential that an ion gradient can produce is the

The maximum membrane potential that an ion gradient can produce is the

The maximum membrane potential that an ion gradient can produce is the 
A) action potential. 
B) membrane potential. 
C) equilibrium potential. 
D) actualized potential. 
E) resting potential.

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The phase at the end of an action potential when the membrane potential becomes more negative than i

The phase at the end of an action potential when the membrane potential becomes more negative than i

The phase at the end of an action potential when the membrane potential becomes more negative than it is at rest is the ________ phase. 
A) threshold 
B) depolarizing 
C) repolarizing 
D) hyperpolarizing&nb

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Which equation best describes the relationship between ion gradient and equilibrium potential for th

Which equation best describes the relationship between ion gradient and equilibrium potential for th

Which equation best describes the relationship between ion gradient and equilibrium potential for that ion? 
A) steady-state 
B) Goldman
C) Nernst   
D) Hodgkin 
E) Katz

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The glial cells associated with phagocytosis to fight infection and remove debris are the

The glial cells associated with phagocytosis to fight infection and remove debris are the

The glial cells associated with phagocytosis to fight infection and remove debris are the 
A) microglia. 
B) oligodendrocytes. 
C) Schwann cells.
D) myelin sheath cells. 
E) astrocytes.

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The somatic nervous system controls

The somatic nervous system controls

The somatic nervous system controls 
A) the brain and spinal cord. 
B) some glands. 
C) skeletal muscles. 
D) cardiac muscle. 
E) smooth muscle.

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Exposure to sarin, a potent nerve gas, results in muscle paralysis. Therefore, sarin must interfere

Exposure to sarin, a potent nerve gas, results in muscle paralysis. Therefore, sarin must interfere

Exposure to sarin, a potent nerve gas, results in muscle paralysis. Therefore, sarin must interfere with which neurotransmitter? 
A) serotonin 
B) GABA   
C) dopamine 
D) enkephalins 
E) glutamate

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You are examining a recently captured organism from another planet and are currently trying to deduc

You are examining a recently captured organism from another planet and are currently trying to deduc

You are examining a recently captured organism from another planet and are currently trying to deduce the types of neurotransmitters associated with the propagation of nerve impulses. You discover a very interesting neurotransmitter and find that, in

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An action potential can always be initiated specifically at which of the following locations associa

An action potential can always be initiated specifically at which of the following locations associa

An action potential can always be initiated specifically at which of the following locations associated with a neuron?
A) ion channels
B) synaptic boutons
C) nodes of Ranvier
D) both choices A and B
E) none of the above

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Multiple sclerosis is a result of

Multiple sclerosis is a result of

Multiple sclerosis is a result of
A) the absence of myelin on nerve cells. 
B) excess amounts of myelin on nerve cells. 
C) an immune system attack on nerve fibers.   
D) blocking the nodes on Ranvier. 

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You treat an organism with a drug that inhibits calcium permeability in nerve cells specifically. As

You treat an organism with a drug that inhibits calcium permeability in nerve cells specifically. As

You treat an organism with a drug that inhibits calcium permeability in nerve cells specifically. As a result, you expect to see 
A) no depolarization of membranes. 
B) no repolarization of membranes. 
C) failure to a

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You stimulate a neuron response by adding a given amount of excitatory neurotransmitter mixed with a

You stimulate a neuron response by adding a given amount of excitatory neurotransmitter mixed with a

You stimulate a neuron response by adding a given amount of excitatory neurotransmitter mixed with a 6x higher concentration of an inhibitory neurotransmitter to the synaptic cleft. You expect that 
A) excitatory responses will travel 1/6

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The stimulation of a neuron by a signal may ultimately stimulate

The stimulation of a neuron by a signal may ultimately stimulate

The stimulation of a neuron by a signal may ultimately stimulate 
A) another nerve cell. 
B) skeletal muscle cells. 
C) gland cells. 
D) smooth muscle cells. 
E) all of the above

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Which of the following is a disease specifically caused by an autoimmune response against acetylchol

Which of the following is a disease specifically caused by an autoimmune response against acetylchol

Which of the following is a disease specifically caused by an autoimmune response against acetylcholine receptors?
A) Grave's disease
B) myasthenia gravis
C) systemic lupus erythematosus
D) Hashimoto's thyroiditis
E

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The sweetener aspartame is a known excitotoxin. With regard to nerve cells, ingestion of this substa

The sweetener aspartame is a known excitotoxin. With regard to nerve cells, ingestion of this substa

The sweetener aspartame is a known excitotoxin. With regard to nerve cells, ingestion of this substance results in chronic nerve stimulation. With your knowledge of action potentials, this toxin must 
A) stimulate continual impulses at the

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A particular neuron does not release neurotransmitters into the synaptic cleft. Further investigatio

A particular neuron does not release neurotransmitters into the synaptic cleft. Further investigatio

A particular neuron does not release neurotransmitters into the synaptic cleft. Further investigation shows that this cell does not respond to calcium ions that are necessary for t- and v-SNARE complex interaction. The most likely problem is associat

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Under times of great stress or shock, which of the following neurotransmitters interferes with the p

Under times of great stress or shock, which of the following neurotransmitters interferes with the p

Under times of great stress or shock, which of the following neurotransmitters interferes with the perception of pain?
A) endocannabinoids
B) GABA
C) catecholamines
D) enkaphalins
E) calcium ions

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The parts of the graph indicated at points C, D, and E represent

The parts of the graph indicated at points C, D, and E represent

The parts of the graph indicated at points C, D, and E represent 
A) depolarization. 
B) hyperpolarization. 
C) the refractory period. 
D) repolarization. 
E) sodium channel activity.

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Refer to the graph above. If the myelin fibers were stripped from this membrane, you would expect th

Refer to the graph above. If the myelin fibers were stripped from this membrane, you would expect th

Refer to the graph above. If the myelin fibers were stripped from this membrane, you would expect the action potential cycle to go 
A) much faster than depicted in the graph. 
B) much faster than normal but not peak at 30 mV.&nb

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In the graph above, at what point in the action potential will the sodium channels be opened?

In the graph above, at what point in the action potential will the sodium channels be opened?

In the graph above, at what point in the action potential will the sodium channels be opened? 
A) A 
B) B 
C) C 
D) D 
E) E

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Based on the graph above, after approximately what period of time could another impulse be propagate

Based on the graph above, after approximately what period of time could another impulse be propagate

Based on the graph above, after approximately what period of time could another impulse be propagated? 
A) 1 msec 
B) 2 msec 
C) 3 msec 
D) 4 msec 
E) immediately following the first stimulation

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In the graph above, the point at which the potassium channels open is indicated by the letter

In the graph above, the point at which the potassium channels open is indicated by the letter

In the graph above, the point at which the potassium channels open is indicated by the letter 
A) A. 
B) B. 
C) C. 
D) D. 
E) E.

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Based on your knowledge of nerve transmission, this movement of ions will

Based on your knowledge of nerve transmission, this movement of ions will

Based on your knowledge of nerve transmission, this movement of ions will 
A) stimulate a change in a postsynaptic membrane. 
B) not stimulate a change in a postsynaptic membrane. 
C) stimulate a change in a postsynap

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