Becker's World of the Cell: Ch 22, 23
1) How many neuronal connections are there in the human brain?
A) millions
B) 1 billion
C) 10 billion
D) 100 billion
E) trillions - ANSWER-e) trillions
1) Inhibitors of which of the following would interfere with nitric oxide stimulation of cardiac artery
dilation through relaxation of smooth muscle cells?
A) protein kinase G.
B) nitric oxide synthase
C) guanylyl cyclase
D) calmodulin
E) Inhibitors of all of the above would interfere with nitric oxide stimulation. - ANSWER-E) Inhibitors
of all of the above would interfere with nitric oxide stimulation.
10) Based on the graph, how soon could another action potential be easily initiated (at the end of
the relative refractory period) after the first stimulus?
A) less than 0.5 msec
B) 1 msec
C) 2 msec
D) 3 msec
E) 4 msec - ANSWER-D) 3 msec
10) Each of the following activates a receptor tyrosine kinase except
A) EGF.
B) PDGF.
C) TGFβ
D) FGF.
E) Insulin. - ANSWER-C) TGFβ
11) Which point on the graph represents the threshold potential?
A) A
B) B
C) C
D) D
,Becker's World of the Cell: Ch 22, 23
E) E - ANSWER-b
12) If myelin was lost from the neuron firing the action potential graphed, the action potential cycle
would
A) go much faster than depicted in the graph.
B) go much faster than normal but not peak at 30 mV.
C) go slower than depicted in the graph.
D) go much slower than normal but peak much higher than 30 mV.
E) remain the same. - ANSWER-E) remain the same.
13) The parts of the graph indicated between points C and E represent
A) depolarization.
B) hyperpolarization.
C) the absolute refractory period.
D) repolarization.
E) sodium channel activity. - ANSWER-D) repolarization.
14) If the membrane represented in the graph was stimulated in the presence of a drug that
specifically inhibits sodium channels, the membrane would
A) not depolarize.
B) depolarize for one stimulus but not for a second stimulus.
C) depolarize but not repolarize.
D) repolarize only to the threshold potential.
E) become permanently hyperpolarized. - ANSWER-A) not depolarize.
15) Each of the following contributes to the unidirectional propagation of nerve signals except
A) dendrites only receive signals.
B) presynaptic neurotransmitter secretion is separated from postsynaptic receptors.
C) neuron membranes have a refractory period following generation of an action potential.
D) ion channels are oriented to transport ions only into the neuron.
E) action potentials initiate the hillock and propagate only down the axon. - ANSWER-D) ion channels
are oriented to transport ions only into the neuron.
16) Compounds that inhibit receptors by preventing the natural messenger from binding are known
as
A) agonists.
B) arrestins.
, Becker's World of the Cell: Ch 22, 23
C) sildenafils.
D) syndecans.
E) antagonists. - ANSWER-E) antagonists.
16) 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) enkephalins
E) acetylcholine - ANSWER-D) enkephalins
17) Each of the following is a step in the epinephrine-cAMP pathway in which the signal is amplified
except
A) receptor activation of G-protein.
B) G-protein activation of adenylyl cyclase.
C) adenylyl cyclase production of cAMP.
D) protein kinase A phosphorylation of target proteins. - ANSWER-B) G-protein activation of adenylyl
cyclase.
17) While characterizing the activities of several neurons, you find a neuron with the following
properties:
(1) When stimulated, the neuron fails to release neurotransmitters into the synaptic cleft.
(2) Microinjection of calcium ions calcium ions has no effect on the neuron. (In other neurons such
microinjection stimulates the t-SNARE and v-SNARE complex interaction that promotes
neurotransmitter secretion.)
The abnormality in this neuron is most likely associated with the function of
A) the vesicle membranes.
B) acetylcholinesterase.
C) synaptotagmin.
D) GABA receptors.
E) gap junctions. - ANSWER-C) synaptotagmin.
18) Each of the following is a G-protein coupled receptor (GPCR) or type of GPCR except
A) steroid hormone receptors.
B) opioid receptors.
C) thyroid-stimulating hormone receptors.
1) How many neuronal connections are there in the human brain?
A) millions
B) 1 billion
C) 10 billion
D) 100 billion
E) trillions - ANSWER-e) trillions
1) Inhibitors of which of the following would interfere with nitric oxide stimulation of cardiac artery
dilation through relaxation of smooth muscle cells?
A) protein kinase G.
B) nitric oxide synthase
C) guanylyl cyclase
D) calmodulin
E) Inhibitors of all of the above would interfere with nitric oxide stimulation. - ANSWER-E) Inhibitors
of all of the above would interfere with nitric oxide stimulation.
10) Based on the graph, how soon could another action potential be easily initiated (at the end of
the relative refractory period) after the first stimulus?
A) less than 0.5 msec
B) 1 msec
C) 2 msec
D) 3 msec
E) 4 msec - ANSWER-D) 3 msec
10) Each of the following activates a receptor tyrosine kinase except
A) EGF.
B) PDGF.
C) TGFβ
D) FGF.
E) Insulin. - ANSWER-C) TGFβ
11) Which point on the graph represents the threshold potential?
A) A
B) B
C) C
D) D
,Becker's World of the Cell: Ch 22, 23
E) E - ANSWER-b
12) If myelin was lost from the neuron firing the action potential graphed, the action potential cycle
would
A) go much faster than depicted in the graph.
B) go much faster than normal but not peak at 30 mV.
C) go slower than depicted in the graph.
D) go much slower than normal but peak much higher than 30 mV.
E) remain the same. - ANSWER-E) remain the same.
13) The parts of the graph indicated between points C and E represent
A) depolarization.
B) hyperpolarization.
C) the absolute refractory period.
D) repolarization.
E) sodium channel activity. - ANSWER-D) repolarization.
14) If the membrane represented in the graph was stimulated in the presence of a drug that
specifically inhibits sodium channels, the membrane would
A) not depolarize.
B) depolarize for one stimulus but not for a second stimulus.
C) depolarize but not repolarize.
D) repolarize only to the threshold potential.
E) become permanently hyperpolarized. - ANSWER-A) not depolarize.
15) Each of the following contributes to the unidirectional propagation of nerve signals except
A) dendrites only receive signals.
B) presynaptic neurotransmitter secretion is separated from postsynaptic receptors.
C) neuron membranes have a refractory period following generation of an action potential.
D) ion channels are oriented to transport ions only into the neuron.
E) action potentials initiate the hillock and propagate only down the axon. - ANSWER-D) ion channels
are oriented to transport ions only into the neuron.
16) Compounds that inhibit receptors by preventing the natural messenger from binding are known
as
A) agonists.
B) arrestins.
, Becker's World of the Cell: Ch 22, 23
C) sildenafils.
D) syndecans.
E) antagonists. - ANSWER-E) antagonists.
16) 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) enkephalins
E) acetylcholine - ANSWER-D) enkephalins
17) Each of the following is a step in the epinephrine-cAMP pathway in which the signal is amplified
except
A) receptor activation of G-protein.
B) G-protein activation of adenylyl cyclase.
C) adenylyl cyclase production of cAMP.
D) protein kinase A phosphorylation of target proteins. - ANSWER-B) G-protein activation of adenylyl
cyclase.
17) While characterizing the activities of several neurons, you find a neuron with the following
properties:
(1) When stimulated, the neuron fails to release neurotransmitters into the synaptic cleft.
(2) Microinjection of calcium ions calcium ions has no effect on the neuron. (In other neurons such
microinjection stimulates the t-SNARE and v-SNARE complex interaction that promotes
neurotransmitter secretion.)
The abnormality in this neuron is most likely associated with the function of
A) the vesicle membranes.
B) acetylcholinesterase.
C) synaptotagmin.
D) GABA receptors.
E) gap junctions. - ANSWER-C) synaptotagmin.
18) Each of the following is a G-protein coupled receptor (GPCR) or type of GPCR except
A) steroid hormone receptors.
B) opioid receptors.
C) thyroid-stimulating hormone receptors.
