BIOL 348 - Exam 3 Questions with Correct Answers.
One example of sensory system encoding is our olfactory system being able to determine
how concentrated an odor is. This is an example of which encoded variable?
A. Intensity
B. Identity
C. Location
D. Intermittency - Correct Answer A. Intensity
Which of the following incorrectly matches the taste sense and the molecule the receptor
for that sense is specific to?
A. Sweet = glucose
B. Savory (umami) = L-glutamate
C. Salty = H+
D. Bitter = cycloheximide - Correct Answer C. Salty = H+
Which of the following sequences correctly describes the signal transduction cascade
involved in sour taste?
A. H+ enters via OTOP1 and blocks K+ channels, causing the membrane to depolarize
and send an AP to gustatory sensory afferents.
B. Na+ enters directly through ENaCs, causing the membrane to depolarize and send an
AP to gustatory sensory afferents.
C. α-gust activates PDE, which triggers Ca2+ release and opens Na+ channels, causing
the membrane to depolarize and send an AP to gustatory sensory afferents.
D. None of the above. - Correct Answer A. H+ enters via OTOP1 and blocks K+ channels,
causing the membrane to depolarize and send an AP to gustatory sensory afferents.
Which of the following statements about contact-mediated chemotropic cues is NOT true?
A. They can be attractive or repulsive.
B. The chance of encountering these cues is definite because growth cones travel on
surfaces.
C. Direct contact with a substrate is not needed.
D. They are signals that exist on a surface. - Correct Answer C. Direct contact with a
substrate is not needed.
What is NOT true of critical periods?
A. They are periods when a specific ability develops
B. There are several critical periods throughout development
C. They require exposure to stimuli that refine processing
D. The brain can always recover from disturbances during critical periods - Correct Answer
D. The brain can always recover from disturbances during critical periods
,Lets say you have two neurons. Neuron 1 has a receptive range that covers a wide range
of stimuli. Neuron 2 has a receptive range that is more restrictive and covers less stimuli.
What is TRUE?
A. Neuron 2 is more selective and has a narrow tuning breadth.
B. Neuron 1 is less selective but more sensitive.
C. Neuron 2 is more selective and has a higher threshold for activation.
D. Neuron 1 is more selective and has a narrow tuning breadth. - Correct Answer A.
Neuron 2 is more selective and has a narrow tuning breadth.
True or false? If sensory receptor neuron 1 requires less stimulus intensity to spike, and
sensory receptor neuron 2 requires more stimulus intensity to spike, then sensory receptor
neuron 1 has a lower threshold for activation. - Correct Answer True
There are two kinds of chemotropic factors that guide axons during development: contact-
mediated cues and long-range cues. Which of the following is a long-range cue?
A. Ephrins
B. Cell adhesion molecules (CAMs)
C. Extracellular matrix adhesion molecules (ECMs)
D. Semaphorins
E. None of the above - Correct Answer A. Ephrins
True or false? Closure of the left eyelid only during the visual critical period will result in less
neurons responding to visual stimuli on the contralateral side of the optic tectum. - Correct
Answer True
What role does Ca2+ have at the NMJ after synapses are formed?
A. Inhibits AchR synthesis to slow down AchR accumulation.
B. Activates MuSK receptors to initiate AchR accumulation.
C. Interacts with rapsyn to initiate gene expression changes.
D. Binds and opens voltage-gated NMJ channels. - Correct Answer A. Inhibits AchR
synthesis to slow down AchR accumulation.
Consider the cytoskeletal morphology of a growth cone.
True or false? When a growth cone encounters an attractive chemotropic cue, the first
change to occur is protrusion of microtubules in the C domain. - Correct Answer False
When the NMJ initially forms, several events occur to establish a strong synapse. Of the
early events below, which one is NOT accurate?
A. Ca2+ influx induces further accumulation of AchRs.
B. Rapsyn proteins are activated and stimulate aggregation of AchRs.
C. Neuregulin signaling induces further accumulation of AchRs.
, D. Presynaptic agrin binds and activates MuSK receptors. - Correct Answer A. Ca2+ influx
induces further accumulation of AchRs.
True or false? Muscle fibers receive input from several MNs after synapses are refined. -
Correct Answer False
Which of the following statements is NOT CORRECT regarding taste receptor cells (TRC)
function?
A. TRC subtypes are organized in a specific manner across the tongue to better
differentiate between the tastes.
B. TRCs respond to contact/surface chemicals.
C. TRCs express several gustatory receptor proteins, making them capable of responding
to different tastes.
D. TRCs encode chemical structure and concentration. - Correct Answer C. TRCs express
several gustatory receptor proteins, making them capable of responding to different
tastes.
Match the sensory system with the physical environmental feature it detects and encodes.
1. Vision
2. Hearing (auditory)
3. Smell (olfactory)
4. Taste (gustatory)
5. Touch (tactile)
a. Surface chemicals
b. Photons
c. Skin displacement
d. Volatile chemicals
e. Pressure waves/particles - Correct Answer 1. B
2. E
3. D
4. A
5. C
When it comes to the integration of visual and auditory cues, why do barn owls that wear
prism glasses during the visual critical period have trouble matching these cues later in
life?
A. Neurons that bridge the space-auditory map shift their tuning, and the auditory map
never recovers.
B. Neurons that form the visual map innervate the auditory map and sense of hearing is
lost.
C. Neurons that sense auditory stimuli die.
One example of sensory system encoding is our olfactory system being able to determine
how concentrated an odor is. This is an example of which encoded variable?
A. Intensity
B. Identity
C. Location
D. Intermittency - Correct Answer A. Intensity
Which of the following incorrectly matches the taste sense and the molecule the receptor
for that sense is specific to?
A. Sweet = glucose
B. Savory (umami) = L-glutamate
C. Salty = H+
D. Bitter = cycloheximide - Correct Answer C. Salty = H+
Which of the following sequences correctly describes the signal transduction cascade
involved in sour taste?
A. H+ enters via OTOP1 and blocks K+ channels, causing the membrane to depolarize
and send an AP to gustatory sensory afferents.
B. Na+ enters directly through ENaCs, causing the membrane to depolarize and send an
AP to gustatory sensory afferents.
C. α-gust activates PDE, which triggers Ca2+ release and opens Na+ channels, causing
the membrane to depolarize and send an AP to gustatory sensory afferents.
D. None of the above. - Correct Answer A. H+ enters via OTOP1 and blocks K+ channels,
causing the membrane to depolarize and send an AP to gustatory sensory afferents.
Which of the following statements about contact-mediated chemotropic cues is NOT true?
A. They can be attractive or repulsive.
B. The chance of encountering these cues is definite because growth cones travel on
surfaces.
C. Direct contact with a substrate is not needed.
D. They are signals that exist on a surface. - Correct Answer C. Direct contact with a
substrate is not needed.
What is NOT true of critical periods?
A. They are periods when a specific ability develops
B. There are several critical periods throughout development
C. They require exposure to stimuli that refine processing
D. The brain can always recover from disturbances during critical periods - Correct Answer
D. The brain can always recover from disturbances during critical periods
,Lets say you have two neurons. Neuron 1 has a receptive range that covers a wide range
of stimuli. Neuron 2 has a receptive range that is more restrictive and covers less stimuli.
What is TRUE?
A. Neuron 2 is more selective and has a narrow tuning breadth.
B. Neuron 1 is less selective but more sensitive.
C. Neuron 2 is more selective and has a higher threshold for activation.
D. Neuron 1 is more selective and has a narrow tuning breadth. - Correct Answer A.
Neuron 2 is more selective and has a narrow tuning breadth.
True or false? If sensory receptor neuron 1 requires less stimulus intensity to spike, and
sensory receptor neuron 2 requires more stimulus intensity to spike, then sensory receptor
neuron 1 has a lower threshold for activation. - Correct Answer True
There are two kinds of chemotropic factors that guide axons during development: contact-
mediated cues and long-range cues. Which of the following is a long-range cue?
A. Ephrins
B. Cell adhesion molecules (CAMs)
C. Extracellular matrix adhesion molecules (ECMs)
D. Semaphorins
E. None of the above - Correct Answer A. Ephrins
True or false? Closure of the left eyelid only during the visual critical period will result in less
neurons responding to visual stimuli on the contralateral side of the optic tectum. - Correct
Answer True
What role does Ca2+ have at the NMJ after synapses are formed?
A. Inhibits AchR synthesis to slow down AchR accumulation.
B. Activates MuSK receptors to initiate AchR accumulation.
C. Interacts with rapsyn to initiate gene expression changes.
D. Binds and opens voltage-gated NMJ channels. - Correct Answer A. Inhibits AchR
synthesis to slow down AchR accumulation.
Consider the cytoskeletal morphology of a growth cone.
True or false? When a growth cone encounters an attractive chemotropic cue, the first
change to occur is protrusion of microtubules in the C domain. - Correct Answer False
When the NMJ initially forms, several events occur to establish a strong synapse. Of the
early events below, which one is NOT accurate?
A. Ca2+ influx induces further accumulation of AchRs.
B. Rapsyn proteins are activated and stimulate aggregation of AchRs.
C. Neuregulin signaling induces further accumulation of AchRs.
, D. Presynaptic agrin binds and activates MuSK receptors. - Correct Answer A. Ca2+ influx
induces further accumulation of AchRs.
True or false? Muscle fibers receive input from several MNs after synapses are refined. -
Correct Answer False
Which of the following statements is NOT CORRECT regarding taste receptor cells (TRC)
function?
A. TRC subtypes are organized in a specific manner across the tongue to better
differentiate between the tastes.
B. TRCs respond to contact/surface chemicals.
C. TRCs express several gustatory receptor proteins, making them capable of responding
to different tastes.
D. TRCs encode chemical structure and concentration. - Correct Answer C. TRCs express
several gustatory receptor proteins, making them capable of responding to different
tastes.
Match the sensory system with the physical environmental feature it detects and encodes.
1. Vision
2. Hearing (auditory)
3. Smell (olfactory)
4. Taste (gustatory)
5. Touch (tactile)
a. Surface chemicals
b. Photons
c. Skin displacement
d. Volatile chemicals
e. Pressure waves/particles - Correct Answer 1. B
2. E
3. D
4. A
5. C
When it comes to the integration of visual and auditory cues, why do barn owls that wear
prism glasses during the visual critical period have trouble matching these cues later in
life?
A. Neurons that bridge the space-auditory map shift their tuning, and the auditory map
never recovers.
B. Neurons that form the visual map innervate the auditory map and sense of hearing is
lost.
C. Neurons that sense auditory stimuli die.
