Bio 546 Final questions n answers
rated A+ 2025/2026
The mechanism by which an action potential moves along a nerve axon is best described as -
correct answer ✔✔domino (wave) effect
An decrease in stimulus strength leads to
a shorter duration of the action potential in a neuron.
a decrease in amplitude of action potentials in a neuron.
a shorter duration of the action potential in a neuron.
an increase in the graded potential in a neuron.
none of the above. - correct answer ✔✔none of the above
The safety factor of an action potential is - correct answer ✔✔the amount of membrane
depolarization during an action potential above what is needed to reach threshold membrane
potential.
What is the function of autoreceptors in synapses?
They speed up the release of neurotransmitters.
They hyperpolarize the postsynaptic membrane.
They slow down the conduction of signals through the electrical synapse.
None of the above. - correct answer ✔✔None of the above
,What is the neurological effect of a chemical that inhibits acetylcholine esterase in the
neuromuscular synapse? - correct answer ✔✔it continues sending impusles to muscles
(seizures)
Acetylcholine is - correct answer ✔✔an excitatory NT for nicotinic receptors
Compared with slow chemical synaptic transmission, a synapse with a FAST chemical
transmission - correct answer ✔✔has relatively small synaptic vesicles releasing their
neurotransmitters close to the receptor proteins.
The sodium/potassium exchange pump in nerve membranes - correct answer ✔✔moves 2 K
ions into the cell for every 3 Na ions moving out.
The reversal potential is the resutl of - correct answer ✔✔opening of lingand-gated NA channels
opening of ligand-gated K channels
Where in neurobiology do you find a negative feedback mechanism? - correct answer ✔✔action
potential
Conduction of action potentials (AP) along a nerve axon requires - correct answer ✔✔a
depolarization large enough to exceed threshold potential leading the AP.
Spatial summation of postsynaptic potentials produces an action potential if ______ - correct
answer ✔✔the summed potential exceeds the threshold potential of the postsynaptic cell.
In which direction does water move across a cell membrane? - correct answer ✔✔From an area
with a low osmolarity to and area with a high osmolarity.
, During the phase of hyper-polarization of the action potential, what flows through the nerve
membrane? - correct answer ✔✔only K current
Saltatory conduction of action potentials in peripheral neurons requires - correct answer
✔✔myelin
Which glial cells produce electrical impulses and cerebrospinal fluid (CSF)?
Microglia
Astrocytes
Satellite cells
Ependymal cells
None of the above. - correct answer ✔✔None of the above
The osmotic pressure of a solution is directly related to its ________ concentration. - correct
answer ✔✔solute
Secondary active transport across a membrane requires - correct answer ✔✔passive transport
primary active transport
A drug that blocks ________ channels will prevent ______ of the neural membrane. - correct
answer ✔✔Na+; depolarization
Choose the incorrect statement regarding EPSPs. - correct answer ✔✔They produce a
hyperpolarization.
The reversal potential differs from the action potential because the reversal potential .... -
correct answer ✔✔reverse the direction of Na ion flow
rated A+ 2025/2026
The mechanism by which an action potential moves along a nerve axon is best described as -
correct answer ✔✔domino (wave) effect
An decrease in stimulus strength leads to
a shorter duration of the action potential in a neuron.
a decrease in amplitude of action potentials in a neuron.
a shorter duration of the action potential in a neuron.
an increase in the graded potential in a neuron.
none of the above. - correct answer ✔✔none of the above
The safety factor of an action potential is - correct answer ✔✔the amount of membrane
depolarization during an action potential above what is needed to reach threshold membrane
potential.
What is the function of autoreceptors in synapses?
They speed up the release of neurotransmitters.
They hyperpolarize the postsynaptic membrane.
They slow down the conduction of signals through the electrical synapse.
None of the above. - correct answer ✔✔None of the above
,What is the neurological effect of a chemical that inhibits acetylcholine esterase in the
neuromuscular synapse? - correct answer ✔✔it continues sending impusles to muscles
(seizures)
Acetylcholine is - correct answer ✔✔an excitatory NT for nicotinic receptors
Compared with slow chemical synaptic transmission, a synapse with a FAST chemical
transmission - correct answer ✔✔has relatively small synaptic vesicles releasing their
neurotransmitters close to the receptor proteins.
The sodium/potassium exchange pump in nerve membranes - correct answer ✔✔moves 2 K
ions into the cell for every 3 Na ions moving out.
The reversal potential is the resutl of - correct answer ✔✔opening of lingand-gated NA channels
opening of ligand-gated K channels
Where in neurobiology do you find a negative feedback mechanism? - correct answer ✔✔action
potential
Conduction of action potentials (AP) along a nerve axon requires - correct answer ✔✔a
depolarization large enough to exceed threshold potential leading the AP.
Spatial summation of postsynaptic potentials produces an action potential if ______ - correct
answer ✔✔the summed potential exceeds the threshold potential of the postsynaptic cell.
In which direction does water move across a cell membrane? - correct answer ✔✔From an area
with a low osmolarity to and area with a high osmolarity.
, During the phase of hyper-polarization of the action potential, what flows through the nerve
membrane? - correct answer ✔✔only K current
Saltatory conduction of action potentials in peripheral neurons requires - correct answer
✔✔myelin
Which glial cells produce electrical impulses and cerebrospinal fluid (CSF)?
Microglia
Astrocytes
Satellite cells
Ependymal cells
None of the above. - correct answer ✔✔None of the above
The osmotic pressure of a solution is directly related to its ________ concentration. - correct
answer ✔✔solute
Secondary active transport across a membrane requires - correct answer ✔✔passive transport
primary active transport
A drug that blocks ________ channels will prevent ______ of the neural membrane. - correct
answer ✔✔Na+; depolarization
Choose the incorrect statement regarding EPSPs. - correct answer ✔✔They produce a
hyperpolarization.
The reversal potential differs from the action potential because the reversal potential .... -
correct answer ✔✔reverse the direction of Na ion flow
