BIO 117 Test Questions with 100% Correct
Answers
which of the following statements is true about sensory neurons and motor neurons
sensory neurons take in information and send it to the CNS, where motor neurons receive
information from the CNS and transmit it to muscle
which neuron structure receives signals directly from other neurons?
dendrite
which statement accurately describes the concentration of potassium ions in a resting
neuron
the concentration of potassium ions is greater in the interior of the cell than in the
extracellular medium
which of the following statements about action potentials is correct
action potentials are propagated down the length of the axon
t/f? for a given neuron, it is possible for one action potential to be smaller in magnitude
or duration than the next
false
the three distinct phases of an action potential occur in what order
depolarization, repolarization, hyperpolarization
the membrane potential in a cell changes from -70 to -60mV, what change has taken
place within the cell
depolarization
, if the membrane potential of a neuron reaches its threshold potential, which event is
most likely to occur next
generation of an action potential
during the process of repolarization ______ ions flood into the ________
potassium ; extracellular matrix
in a neuron at rest, what accurately describes the relative concentration of ions
potassium has a relatively high concentration while sodium and chlorine have relatively low
concentrations
for a neuron at rest with a membrane potential of -65 mV, an increase in the movement
of potassium ions out of that neuron's cytoplasm would result in the ________.
hyperpolarization of the membrane
what happens at the peak of an action potential
many sodium ion channels begin to close and many potassium ion channels begin to open.
indicate what happens at each point during an action potential
1. Na+/K+ pumps and K+ leak channels are maintaining the membrane potential
2. The membrane potential is approaching -55 mV
3. Voltage gated Na+ channels open rapidly; Na+ rushes into the cell
4. Voltage gated Na+ channels close
5. Voltage gated K+ channels open;K+ rushes out of the cell
6. Refractory period where membrane potential is below resting potential prevents re-firing
too soon
Answers
which of the following statements is true about sensory neurons and motor neurons
sensory neurons take in information and send it to the CNS, where motor neurons receive
information from the CNS and transmit it to muscle
which neuron structure receives signals directly from other neurons?
dendrite
which statement accurately describes the concentration of potassium ions in a resting
neuron
the concentration of potassium ions is greater in the interior of the cell than in the
extracellular medium
which of the following statements about action potentials is correct
action potentials are propagated down the length of the axon
t/f? for a given neuron, it is possible for one action potential to be smaller in magnitude
or duration than the next
false
the three distinct phases of an action potential occur in what order
depolarization, repolarization, hyperpolarization
the membrane potential in a cell changes from -70 to -60mV, what change has taken
place within the cell
depolarization
, if the membrane potential of a neuron reaches its threshold potential, which event is
most likely to occur next
generation of an action potential
during the process of repolarization ______ ions flood into the ________
potassium ; extracellular matrix
in a neuron at rest, what accurately describes the relative concentration of ions
potassium has a relatively high concentration while sodium and chlorine have relatively low
concentrations
for a neuron at rest with a membrane potential of -65 mV, an increase in the movement
of potassium ions out of that neuron's cytoplasm would result in the ________.
hyperpolarization of the membrane
what happens at the peak of an action potential
many sodium ion channels begin to close and many potassium ion channels begin to open.
indicate what happens at each point during an action potential
1. Na+/K+ pumps and K+ leak channels are maintaining the membrane potential
2. The membrane potential is approaching -55 mV
3. Voltage gated Na+ channels open rapidly; Na+ rushes into the cell
4. Voltage gated Na+ channels close
5. Voltage gated K+ channels open;K+ rushes out of the cell
6. Refractory period where membrane potential is below resting potential prevents re-firing
too soon
