Final Exam BIOL 546 questions and answers
2024\2025 A+ Grade
What best describes homeostasis
- correct answer organisms maintain a narrow range of internal conditions
the diffusion rate of chemical X across a cell membrane can be increased by
- correct answer decreases the concentration gradient for X across the membrane
placing red blood cells in a hypotonic solution would cause them to
- correct answer first swell, then shrink
graded potential
- correct answer are local changes in membrane potential that occurs in varying degrees of magnitude
and can be depolarization or hyperpolarizations
what can stop the Hodgkin cycle
- correct answer inactivation of Na channels and activation of K channels
conduction of AP along a nerve axon requires
- correct answer a depolarization large enough to excess the threshold potential leading to the AP
If an AP was initiated at the axon hillock by a grade potential coming from the cell body, what direction
would the AP travel
- correct answer away from the cell body
if an AP was initiated at the center of the axon, what direction would it travel
- correct answer both direction
If a neuron were experimentally stimulated at both ends simultaneously
- correct answer the Ads would stop as they meet in the middle
,what is the neurological effect of a chemical such as sarin, the inhibits AChE in the neuromuscular
synapse
- correct answer nerve continues to send impulse to the muscles (seizures)
what determines if a synapse is excitatory or inhibitory
- correct answer type of NT and type of ion channel opened by the postsynaptic receptor activated by
NT
the vertebrate neural system conducts signals in only one direction. This one way signaling occurs
- correct answer as a result of voltage gated Na Channels, bc the postsynaptic ending cannot release NT,
bv only the postsynaptic membrane can bind NT
All of the following are true statements about the action potential EXCEPT:
a) Opening of the voltage-gated Na-channels will move the membrane potential to the equilibrium
potential of Na.
b) Opening of voltage-gated K-channels will move the membrane potential to the equilibrium potential
of K.
c) The Hodgkin cycle causes the fast change in membrane potential during the rising phase of the action
potential.
d) The falling phase of the AP is mainly due to the movement of K+ ions.
e) Voltage-gated Na-channels stay open longer than voltage-gated K-channels.
- correct answer e) Voltage-gated Na-channels stay open longer than voltage-gated K-channels.
Scientists discovered a new animal species with nerve cells physiologically similar to nerve cells found in
other animals. The membrane potential when only sodium ions can move across the membrane was
measured at +116 mV. What is the sodium concentration outside the nerve cell if the sodium
concentration inside the cell is 1 mM?
a) 1 M
b) 0.232 M
c) 0.116 M
d) 0.58 M
e) 0.1 M
- correct answer e) 0.1 M
,3. Which neurotransmitter binds to the nicotinic ACh receptor?
a) muscarine
b) atopine
c) norepinephrine
d) glutamate
e) None of the above
- correct answer e) None of the above ***
4. 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 cone cell by blue light results in the production of an action potential in the connected
bipolar cell.
a) true
b) false
- correct answer F
6. Which concept is the defining feature of the discipline of physiology?
a) Descent with modification
b) Homeostasis
c) Evolution
d) Equilibrium
e) Differentiation
- correct answer homeostasis
, 7. 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. ***
8. What is the general purpose of positive feedback mechanisms?
a) To maintain a constant internal environment
b) To anticipate changes in the environment
c) To return a variable toward the set point
d) To bring about a rapid change in the body
e) To detect changes in the external environment
- correct answer d) To bring about a rapid change in the body
9. You are designing a drug. You'd like to deliver the drug by creating a skin patch that is impregnated
with the drug and allowing 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 ***
10. What comes last in the release of neurotransmitters from synaptic vesicles?
a) fusion.
b) priming.
c) docking
2024\2025 A+ Grade
What best describes homeostasis
- correct answer organisms maintain a narrow range of internal conditions
the diffusion rate of chemical X across a cell membrane can be increased by
- correct answer decreases the concentration gradient for X across the membrane
placing red blood cells in a hypotonic solution would cause them to
- correct answer first swell, then shrink
graded potential
- correct answer are local changes in membrane potential that occurs in varying degrees of magnitude
and can be depolarization or hyperpolarizations
what can stop the Hodgkin cycle
- correct answer inactivation of Na channels and activation of K channels
conduction of AP along a nerve axon requires
- correct answer a depolarization large enough to excess the threshold potential leading to the AP
If an AP was initiated at the axon hillock by a grade potential coming from the cell body, what direction
would the AP travel
- correct answer away from the cell body
if an AP was initiated at the center of the axon, what direction would it travel
- correct answer both direction
If a neuron were experimentally stimulated at both ends simultaneously
- correct answer the Ads would stop as they meet in the middle
,what is the neurological effect of a chemical such as sarin, the inhibits AChE in the neuromuscular
synapse
- correct answer nerve continues to send impulse to the muscles (seizures)
what determines if a synapse is excitatory or inhibitory
- correct answer type of NT and type of ion channel opened by the postsynaptic receptor activated by
NT
the vertebrate neural system conducts signals in only one direction. This one way signaling occurs
- correct answer as a result of voltage gated Na Channels, bc the postsynaptic ending cannot release NT,
bv only the postsynaptic membrane can bind NT
All of the following are true statements about the action potential EXCEPT:
a) Opening of the voltage-gated Na-channels will move the membrane potential to the equilibrium
potential of Na.
b) Opening of voltage-gated K-channels will move the membrane potential to the equilibrium potential
of K.
c) The Hodgkin cycle causes the fast change in membrane potential during the rising phase of the action
potential.
d) The falling phase of the AP is mainly due to the movement of K+ ions.
e) Voltage-gated Na-channels stay open longer than voltage-gated K-channels.
- correct answer e) Voltage-gated Na-channels stay open longer than voltage-gated K-channels.
Scientists discovered a new animal species with nerve cells physiologically similar to nerve cells found in
other animals. The membrane potential when only sodium ions can move across the membrane was
measured at +116 mV. What is the sodium concentration outside the nerve cell if the sodium
concentration inside the cell is 1 mM?
a) 1 M
b) 0.232 M
c) 0.116 M
d) 0.58 M
e) 0.1 M
- correct answer e) 0.1 M
,3. Which neurotransmitter binds to the nicotinic ACh receptor?
a) muscarine
b) atopine
c) norepinephrine
d) glutamate
e) None of the above
- correct answer e) None of the above ***
4. 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 cone cell by blue light results in the production of an action potential in the connected
bipolar cell.
a) true
b) false
- correct answer F
6. Which concept is the defining feature of the discipline of physiology?
a) Descent with modification
b) Homeostasis
c) Evolution
d) Equilibrium
e) Differentiation
- correct answer homeostasis
, 7. 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. ***
8. What is the general purpose of positive feedback mechanisms?
a) To maintain a constant internal environment
b) To anticipate changes in the environment
c) To return a variable toward the set point
d) To bring about a rapid change in the body
e) To detect changes in the external environment
- correct answer d) To bring about a rapid change in the body
9. You are designing a drug. You'd like to deliver the drug by creating a skin patch that is impregnated
with the drug and allowing 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 ***
10. What comes last in the release of neurotransmitters from synaptic vesicles?
a) fusion.
b) priming.
c) docking
