Download ch 48 clicker questions

CLICKER QUESTIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 48
Neurons, Synapses, and
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Signaling
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Questions prepared by
Christopher Gregg
Louisiana State University
John Lepri
University of North Carolina, Greensboro
© 2011 Pearson Education, Inc.
Choose the correct pathway of information flow
through neurons while taking a test, starting with
reading a question and ending with marking an
answer.
a) interneurons  motor neurons  sensory neurons  effectors
b) effectors  sensory neurons  interneurons  motor neurons
c) sensory neurons  interneurons  motor neurons  effectors
d) interneurons  sensory neurons  motor neurons  effectors
© 2011 Pearson Education, Inc.
Adding a poison that specifically disables the
Na+/K+ pumps to a culture of neurons will
cause
a) the resting membrane potential to drop to 0 mV.
b) the inside of the neuron to become more negative
relative to the outside.
c) the inside of the neuron to become positively
charged relative to the outside.
d) sodium to diffuse out of the cell and potassium to
diffuse into the cell.
© 2011 Pearson Education, Inc.
For a nerve cell at its resting potential, the
forces acting on potassium ions (K+) are
a) none: K+ ions do not move at the resting potential.
b) an electrical gradient, pulling K+ inward, and a
chemical gradient, pushing K+ outward.
c) an electrical gradient, pushing K+ outward, and a
chemical gradient, pulling K+ inward.
d) an electrical gradient, pulling K+ inward, and a
chemical gradient, pushing K+ outward.
e) an electrical gradient, pushing K+ outward, and a
chemical gradient, pushing K+ outward.
© 2011 Pearson Education, Inc.
A(n) ___ in Na+ permeability and/or a(n)
___ in K+ permeability across a neuron’s
plasma membrane could shift membrane
potential from −70 mV to −80 mV.
a) increase; increase
b) increase; decrease
c) decrease; increase
d) decrease; decrease
© 2011 Pearson Education, Inc.
At time ZERO msec on the graph, it is likely
that there was
a) a localized opening of
K+ channels.
b) a localized opening of
some Na+ channels.
c) a rapid opening of
most K+ channels.
d) a rapid opening of
most Na+ channels.
© 2011 Pearson Education, Inc.
At step four in the
graph, it is likely that
a) most Cl− channels closed.
b) most Na+ channels opened.
c) most K+ channels closed.
d) most K+ channels opened.
e) Na/K pumps were
inactivated.
© 2011 Pearson Education, Inc.
Of the following choices, the slowest
conduction velocity for moving action potentials is
likely seen in
a) a large-diameter, nonmyelinated axon.
b) a small-diameter, nonmyelinated axon.
c) A myelinated axon.
d) any of the above, as all neurons conduct action
potentials at the same speed.
© 2011 Pearson Education, Inc.
Injecting ethylene glycol tetraacetic acid (EGTA),
a chelating agent that prevents calcium ions from
moving across membranes, to a synaptic region
would likely
a) increase the release of neurotransmitters by the
presynaptic neuron.
b) decrease the release of neurotransmitters by the
presynaptic neuron.
c) result in neurotransmitters being released, but could not
bind to its receptors on the post synaptic neuron.
d) result in the lack of calcium ions keeping the ligandgated ion channels open on the post synaptic neurons.
© 2011 Pearson Education, Inc.
The use of organophosphate pesticides that inhibit
acetylcholinesterase, an enzyme that breaks down
acetylcholine, could cause skeletal muscle cells to
a) undergo more graded depolarizations, because acetylcholine
would remain in the synaptic cleft longer.
b) undergo more graded hyperpolarizations, because
acetylcholine would remain in the synaptic cleft longer.
c) undergo more graded depolarizations, because acetylcholine
would prevent ligand-gated ion channels from opening.
d) undergo more graded hyperpolarizations, because excess
acetylcholine opens Cl− channels.
© 2011 Pearson Education, Inc.
Adderall, an amphetamine stimulant, works
on the CNS by
a) increasing the release of GABA and decreasing its
catabolism/reuptake.
b) increasing the release of serotonin and decreasing
its catabolism/reuptake.
c) increasing the release of endorphins and decreasing
their catabolism/reuptake.
d) increasing the release of dopamine and
norepinephrine and decreasing their
catabolism/reuptake.
© 2011 Pearson Education, Inc.