Bio Sci E109 Module 1 2 Questions and Answers
Question 1.
Is the distance between a chemical synapse and the axon hillock important for whether an
action potential is generated?
Correct Answer: Yes, changes in Vm in the dendrites depend on diffusion, which
varies with distance.
Question 2.
By what factor would the rate of diffusion change if membrane thickness increased by a
factor of 5?
Correct Answer: 0.200
Question 3.
What proteins bind epithelial cells together to provide a strong membrane and chemical
barrier? Gap junctions Cross-junctions Desmosomes Tight junctions
Correct Answer: Desmosomes Tight junctions
Question 4.
Which of the following are types of epithelia? Protective Secretory Contractile Exchange
Ciliated
Correct Answer: Protective Secretory Exchange Ciliated
Question 5.
Increases in which of the following increase the rate of chemical diffusion? Molecular mass
Temperature
Correct Answer: Temperature
Question 6.
The release of a neurotransmitter at a chemical synapse by a presynaptic cell includes
which of the following components? regulatory (i.e., motor) proteins Ca2+ ions vesicles
hormones Docking protein.
Correct Answer: regulatory (i.e., motor) proteins Ca2+ ions vesicles Docking
protein.
Question 7.
How would the equilibrium potential for potassium (EK+) change if the concentration of
that ion increased outside of a cell?
Correct Answer: It would increase
Question 8.
Which statement(s) are FALSE? Action potentials travel in 2 directions routinely. An action
potential amplitude can vary with the strength of the stimulus. An action potential
measured at the distal end of an axon is identical to one measured at the spike-initiating
zone. All action pot
Correct Answer: Action potentials travel in 2 directions routinely. An action
potential amplitude can vary with the strength of the stimulus.
, Question 9.
Which of the following factors increase the rate of diffusion across a membrane?
Increasing membrane permeability Increasing the solute concentration difference across
the membrane Increasing membrane thickness Increasing the membrane area
Correct Answer: Increasing membrane permeability Increasing the solute
concentration difference across the membrane Increasing the membrane area
Question 10.
Which statements are TRUE of the axon hillock? It blocks changes in the membrane
potential in the dendrites that could be caused by channels in the axon. It is the site of
action potentials between the glial cells that mylinate the axon. It is the site of synapse
formation in the presynaptic cell. It initiates an action potential when its membrane
potential exceeds a threshold.
Correct Answer: It initiates an action potential when its membrane potential
exceeds a threshold.
Question 11.
This figure illustrates an electrophysiological recording of the membrane potential of an
axon. During depolarization, what best accounts for the change in slope in Vm as the
membrane reaches threshold?
Correct Answer: Na+ permeability changes
Question 12.
What is NOT of the Nernst equation? It considers the valence (i.e. charge) of an ion. It
models the voltage generated by a difference in ion concentration across a membrane. Its
predictions depend on temperature. It calculates the membrane potential for ions of
different permeability.
Correct Answer: It calculates the membrane potential for ions of different
permeability.
Question 13.
Match the following characteristics to either Carrier, Channel membrane proteins, or both.
1.Change confirmation 2.Allow ions to leak 3.Transmembrane protein
Correct Answer: 1.Carrier Proteins 2.Channel Proteins 3.Both
Question 14.
Select which statement is not true about action potentials Voltage-gated channels for Na+
and K+ have a similar threshold Vm. The inactivation gate reduces permeability in the
voltage-gated K+ channel Repolarization is driven by K+ permeability. Depolarization
would not happen if not for voltage-gated Na+ channels.
Correct Answer: The inactivation gate reduces permeability in the voltage-gated
K+ channel
Question 15.
This figure illustrates an electrophysiological experiment with measurements of the
concentration differences on the inside (in gray) and outside (in white) of a neuron.
Increasing the density of potassium leak channels will depolarize the cell membrane.
Correct Answer: False
Question 1.
Is the distance between a chemical synapse and the axon hillock important for whether an
action potential is generated?
Correct Answer: Yes, changes in Vm in the dendrites depend on diffusion, which
varies with distance.
Question 2.
By what factor would the rate of diffusion change if membrane thickness increased by a
factor of 5?
Correct Answer: 0.200
Question 3.
What proteins bind epithelial cells together to provide a strong membrane and chemical
barrier? Gap junctions Cross-junctions Desmosomes Tight junctions
Correct Answer: Desmosomes Tight junctions
Question 4.
Which of the following are types of epithelia? Protective Secretory Contractile Exchange
Ciliated
Correct Answer: Protective Secretory Exchange Ciliated
Question 5.
Increases in which of the following increase the rate of chemical diffusion? Molecular mass
Temperature
Correct Answer: Temperature
Question 6.
The release of a neurotransmitter at a chemical synapse by a presynaptic cell includes
which of the following components? regulatory (i.e., motor) proteins Ca2+ ions vesicles
hormones Docking protein.
Correct Answer: regulatory (i.e., motor) proteins Ca2+ ions vesicles Docking
protein.
Question 7.
How would the equilibrium potential for potassium (EK+) change if the concentration of
that ion increased outside of a cell?
Correct Answer: It would increase
Question 8.
Which statement(s) are FALSE? Action potentials travel in 2 directions routinely. An action
potential amplitude can vary with the strength of the stimulus. An action potential
measured at the distal end of an axon is identical to one measured at the spike-initiating
zone. All action pot
Correct Answer: Action potentials travel in 2 directions routinely. An action
potential amplitude can vary with the strength of the stimulus.
, Question 9.
Which of the following factors increase the rate of diffusion across a membrane?
Increasing membrane permeability Increasing the solute concentration difference across
the membrane Increasing membrane thickness Increasing the membrane area
Correct Answer: Increasing membrane permeability Increasing the solute
concentration difference across the membrane Increasing the membrane area
Question 10.
Which statements are TRUE of the axon hillock? It blocks changes in the membrane
potential in the dendrites that could be caused by channels in the axon. It is the site of
action potentials between the glial cells that mylinate the axon. It is the site of synapse
formation in the presynaptic cell. It initiates an action potential when its membrane
potential exceeds a threshold.
Correct Answer: It initiates an action potential when its membrane potential
exceeds a threshold.
Question 11.
This figure illustrates an electrophysiological recording of the membrane potential of an
axon. During depolarization, what best accounts for the change in slope in Vm as the
membrane reaches threshold?
Correct Answer: Na+ permeability changes
Question 12.
What is NOT of the Nernst equation? It considers the valence (i.e. charge) of an ion. It
models the voltage generated by a difference in ion concentration across a membrane. Its
predictions depend on temperature. It calculates the membrane potential for ions of
different permeability.
Correct Answer: It calculates the membrane potential for ions of different
permeability.
Question 13.
Match the following characteristics to either Carrier, Channel membrane proteins, or both.
1.Change confirmation 2.Allow ions to leak 3.Transmembrane protein
Correct Answer: 1.Carrier Proteins 2.Channel Proteins 3.Both
Question 14.
Select which statement is not true about action potentials Voltage-gated channels for Na+
and K+ have a similar threshold Vm. The inactivation gate reduces permeability in the
voltage-gated K+ channel Repolarization is driven by K+ permeability. Depolarization
would not happen if not for voltage-gated Na+ channels.
Correct Answer: The inactivation gate reduces permeability in the voltage-gated
K+ channel
Question 15.
This figure illustrates an electrophysiological experiment with measurements of the
concentration differences on the inside (in gray) and outside (in white) of a neuron.
Increasing the density of potassium leak channels will depolarize the cell membrane.
Correct Answer: False
