500 Questions & Answers | Introductory
Physiology | 2026-2027 Edition
This comprehensive practice test contains 500 verified questions and answers for
the WVU BIOL 117 Introductory Physiology Final Exam. The questions cover all
essential domains including cell physiology, neurobiology, plant physiology,
osmoregulation, endocrinology, immunology, circulation, respiration, excretion,
reproduction, and evolution . Each question includes a detailed rationale to
reinforce learning and ensure exam readiness.
SECTION 1: CELL PHYSIOLOGY & NEUROBIOLOGY (Questions 1-100)
Question 1: 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:
A) Depolarization of the neuron
B) Hyperpolarization of the neuron
C) An action potential
D) No change in membrane potential
Correct Answer: B) Hyperpolarization of the neuron
Rationale: Moving potassium ions out of the neuron makes the interior more
negative, resulting in hyperpolarization . This occurs because potassium is a
positively charged ion, and its exit leaves behind more negative charges inside the
cell.
,Question 2: The operation of the sodium-potassium pump moves:
A) Sodium ions into the cell and potassium ions out of the cell
B) Sodium ions out of the cell and potassium ions into the cell
C) Both sodium and potassium ions out of the cell
D) Both sodium and potassium ions into the cell
Correct Answer: B) Sodium ions out of the cell and potassium ions into the cell
Rationale: The sodium-potassium pump actively transports 3 Na+ out of the cell
and 2 K+ into the cell, consuming ATP in the process . This maintains the resting
membrane potential and concentration gradients essential for neuronal function.
Question 3: A common feature of action potentials is that they:
A) Are triggered by a depolarization that reaches the threshold potential
B) Are triggered by hyperpolarization
C) Require no stimulus to occur
D) Are all-or-none but graded in amplitude
Correct Answer: A) Are triggered by a depolarization that reaches the threshold
potential
,Rationale: Action potentials are triggered when depolarization of the membrane
reaches a specific threshold potential. At this point, voltage-gated sodium
channels open, initiating the action potential .
Question 4: Why do Na+ ions enter the cell when voltage-gated Na+ channels are
opened in neurons?
A) Because the Na+ concentration is much higher outside the cell than it is inside,
and the Na+ ions are attracted to the negatively charged interior
B) Because the Na+ concentration is higher inside the cell
C) Because Na+ ions are actively transported into the cell
D) Because Na+ ions move down their electrical gradient only
Correct Answer: A) Because the Na+ concentration is much higher outside the cell
than it is inside, and the Na+ ions are attracted to the negatively charged interior
Rationale: Sodium ions enter the cell due to both chemical (concentration
gradient, higher outside) and electrical (inside is more negative) gradients. These
driving forces pull Na+ into the cell during depolarization .
Question 5: In a synapse, neurotransmitter chemicals are received by:
A) The presynaptic membrane
B) The postsynaptic membrane
C) The synaptic cleft
D) The axon hillock
, Correct Answer: B) The postsynaptic membrane
Rationale: Neurotransmitters are released from the presynaptic membrane into
the synaptic cleft and bind to receptors on the postsynaptic membrane of the
receiving neuron . This binding initiates the postsynaptic response, which can be
excitatory or inhibitory.
Question 6: Tetrodotoxin blocks voltage-gated sodium channels and ouabain
blocks sodium-potassium pumps. If you added both tetrodotoxin and ouabain to a
solution containing neural tissue, what responses would you expect?
A) Immediate loss of action potential with gradual loss of resting potential
B) Immediate loss of resting potential with gradual loss of action potential
C) Complete and immediate loss of both action and resting potential
D) No effect on either potential
Correct Answer: A) Immediate loss of action potential with gradual loss of resting
potential
Rationale: Tetrodotoxin blocks action potentials immediately by preventing Na+
influx. Ouabain blocks the Na+/K+ pump, which gradually dissipates the resting
membrane potential over time as ion gradients equilibrate .
Question 7: Why does the presence of a myelin sheath increase the speed at
which a nerve impulse travels?