BIOL 546 FINAL EXAM QUESTIONS
WITH CORRECT ANSWERS 2025/2026
What is the correct sequence of events during an excitatory synaptic transmission at the
chemical synapse?
(1) The AP reaches the presynaptic terminal, (2) depolarization produces an EPSP, (3) Ca2+
channels are activated by depolarization, (4) the neurotransmitter (NT) diffuses across the
synaptic cleft, (5) Ca2+ influx into the presynaptic terminal, (6) synaptic vesicles fuse with the
presynaptic membrane, (7) binding of NT to postsynaptic receptors.
a) 1 - 4 - 3 - 6 - 7 - 5 - 2
b) 1 - 3 - 7 - 6 - 5 - 2 - 4
c) 6 - 3 - 5 - 2 - 4 - 7 - 1
d) 7 - 5 - 4 - 3 - 4 - 1 - 2
e) 1 - 3 - 5 - 6 - 4 - 7 -2 - correct answer ✔✔e) 1-3-5-6-4-7-2
The function of auto receptors is to....
a) automatically depolarize the postsynaptic membrane
b) control the release of neurotransmitter
c) start the uptake of neurotransmitter
d) block an antagonist - correct answer ✔✔b. control the release of neurotransmitter
The diffusion rate of chemical X across a cell membrane can de decreased by:
,a) increasing the membrane permeability of X.
b) increasing the concentration gradient for X across the membrane.
c) increasing the area of diffusion.
d) increasing the thickness of the membrane.
e) decreasing the thickness of the membrane. - correct answer ✔✔d) increasing the thickness
of the membrane
Placing human red blood cells in a hypotonic solution would cause them to...
a) swell.
b) shrink.
c) stay the same size - correct answer ✔✔a) swell
Which is TRUE about the Na+, K+, ATPase pump in neurons?
a) It generates a small electrical potential such that the inside is made negative with respect to
the outside.
b) It maintains a concentration gradient for K+ such that diffusion forces favor movement of K+
into the cell.
c) It maintains an electrical gradient at the equilibrium potential of K+.
d) It transports equal numbers of sodium and potassium ions with each pump cycle.
e) It pumps 3 Na+ ions into the cell for every 2 K+ ions it pumps out. - correct answer ✔✔a) it
generates a small electrical potential such that the inside is made negative with respect to the
outside
Which feature is found in ionotropic receptors, but NOT in metabotropic receptors?
a) Neurotransmitter binding results is opening of ion channels using activation of G proteins.
,b) Neurotransmitter binding results in opening of receptor-associated ion channels.
c) Neurotransmitter binding results in the production of 2nd messenger.
d) Answers a and c. - correct answer ✔✔b) neurotransmitter binding results in opening of
receptor-associated ion channels
The period of excitability of neuron during which both Na+ and K+ activation can occur is called
the...
a) interphase period.
b) relative refractory period.
c) absolute refractory period.
d) hyperexcitable period.
e) latent period - correct answer ✔✔b) relative refractory period
Excitation of the rod cell by blue light results in the production of an action potential in the
connected bipolar cell.
a) true
b) false - correct answer ✔✔b) false
The process that produces the most ATP molecules per molecule of glucose is...
a) substrate-level phosphorylation.
b) oxidative phosphorylation.
c) anaerobic glycolysis.
d) aerobic glycolysis.
e) Krebs (citric acid) cycle. - correct answer ✔✔b) oxidative phosphorylation
, Stimulation of a hair cell results in changes in the hair cell membrane such as...
a) opening of voltage-gated Na+ channels.
b) opening of voltage-gated K+ channels.
c) answers a and b.
d) none of the above. - correct answer ✔✔d) none of the above
You are designing a drug. You would like to deliver the drug by creating a skin patch that
contains the drug and allows the drug to diffuse through the layers of the skin to reach the
underlying tissues and bloodstream. Which of these chemical changes might you make to
increase the number of drug molecules that diffuse through the layers of skin cells?
a) Increasing the number of nitrogen atoms in the drug
b) Decreasing the number of nonpolar groups in the drug
c) Decreasing the number of polar groups in the drug
d) Increasing the number of oxygen atoms in the drug - correct answer ✔✔c) decreasing the
number of polar groups in the drug
What comes first in the release of neurotransmitters from synaptic vesicles?
a) fusion.
b) priming.
c) docking.
d) opening of K+ channels - correct answer ✔✔c) docking
All of the following are true statements about the action potential EXCEPT:
WITH CORRECT ANSWERS 2025/2026
What is the correct sequence of events during an excitatory synaptic transmission at the
chemical synapse?
(1) The AP reaches the presynaptic terminal, (2) depolarization produces an EPSP, (3) Ca2+
channels are activated by depolarization, (4) the neurotransmitter (NT) diffuses across the
synaptic cleft, (5) Ca2+ influx into the presynaptic terminal, (6) synaptic vesicles fuse with the
presynaptic membrane, (7) binding of NT to postsynaptic receptors.
a) 1 - 4 - 3 - 6 - 7 - 5 - 2
b) 1 - 3 - 7 - 6 - 5 - 2 - 4
c) 6 - 3 - 5 - 2 - 4 - 7 - 1
d) 7 - 5 - 4 - 3 - 4 - 1 - 2
e) 1 - 3 - 5 - 6 - 4 - 7 -2 - correct answer ✔✔e) 1-3-5-6-4-7-2
The function of auto receptors is to....
a) automatically depolarize the postsynaptic membrane
b) control the release of neurotransmitter
c) start the uptake of neurotransmitter
d) block an antagonist - correct answer ✔✔b. control the release of neurotransmitter
The diffusion rate of chemical X across a cell membrane can de decreased by:
,a) increasing the membrane permeability of X.
b) increasing the concentration gradient for X across the membrane.
c) increasing the area of diffusion.
d) increasing the thickness of the membrane.
e) decreasing the thickness of the membrane. - correct answer ✔✔d) increasing the thickness
of the membrane
Placing human red blood cells in a hypotonic solution would cause them to...
a) swell.
b) shrink.
c) stay the same size - correct answer ✔✔a) swell
Which is TRUE about the Na+, K+, ATPase pump in neurons?
a) It generates a small electrical potential such that the inside is made negative with respect to
the outside.
b) It maintains a concentration gradient for K+ such that diffusion forces favor movement of K+
into the cell.
c) It maintains an electrical gradient at the equilibrium potential of K+.
d) It transports equal numbers of sodium and potassium ions with each pump cycle.
e) It pumps 3 Na+ ions into the cell for every 2 K+ ions it pumps out. - correct answer ✔✔a) it
generates a small electrical potential such that the inside is made negative with respect to the
outside
Which feature is found in ionotropic receptors, but NOT in metabotropic receptors?
a) Neurotransmitter binding results is opening of ion channels using activation of G proteins.
,b) Neurotransmitter binding results in opening of receptor-associated ion channels.
c) Neurotransmitter binding results in the production of 2nd messenger.
d) Answers a and c. - correct answer ✔✔b) neurotransmitter binding results in opening of
receptor-associated ion channels
The period of excitability of neuron during which both Na+ and K+ activation can occur is called
the...
a) interphase period.
b) relative refractory period.
c) absolute refractory period.
d) hyperexcitable period.
e) latent period - correct answer ✔✔b) relative refractory period
Excitation of the rod cell by blue light results in the production of an action potential in the
connected bipolar cell.
a) true
b) false - correct answer ✔✔b) false
The process that produces the most ATP molecules per molecule of glucose is...
a) substrate-level phosphorylation.
b) oxidative phosphorylation.
c) anaerobic glycolysis.
d) aerobic glycolysis.
e) Krebs (citric acid) cycle. - correct answer ✔✔b) oxidative phosphorylation
, Stimulation of a hair cell results in changes in the hair cell membrane such as...
a) opening of voltage-gated Na+ channels.
b) opening of voltage-gated K+ channels.
c) answers a and b.
d) none of the above. - correct answer ✔✔d) none of the above
You are designing a drug. You would like to deliver the drug by creating a skin patch that
contains the drug and allows the drug to diffuse through the layers of the skin to reach the
underlying tissues and bloodstream. Which of these chemical changes might you make to
increase the number of drug molecules that diffuse through the layers of skin cells?
a) Increasing the number of nitrogen atoms in the drug
b) Decreasing the number of nonpolar groups in the drug
c) Decreasing the number of polar groups in the drug
d) Increasing the number of oxygen atoms in the drug - correct answer ✔✔c) decreasing the
number of polar groups in the drug
What comes first in the release of neurotransmitters from synaptic vesicles?
a) fusion.
b) priming.
c) docking.
d) opening of K+ channels - correct answer ✔✔c) docking
All of the following are true statements about the action potential EXCEPT:
