BIOL 246 Exam 2 Practice Test | Latest 2026/27
Qs & Ans ( PDF) | Graded A+
1. If a neuron is stimulated experimentally at both ends simultaneously to
generate action potentials, what would you expect to happen?
the two action potentials will meet in the middle and die off.
on meeting together, they will both travel towards the axon terminals.
stronger action potential will override the weaker one and travel to the
opposite side.
the two action potentials will meet in the middle and continue traveling to
the other side.
2. Temporal summation of postsynaptic potentials _____
occurs when a single neuron releases a neurotransmitter more than
once and in rapid succession
occurs because of the convergence of many neurons on a single postsynaptic
cell
only involves excitatory postsynaptic potentials
only involves inhibitory postsynaptic potentials
3. Which type of cells are responsible for the formation of myelin sheaths in the
central nervous system (CNS)?
Schwann cells
oligodendrocytes
astrocytes
microglia
,4. Which of the following CORRECTLY explains how cells of the inner ear
detect sound?
Every Hair cell detects high and low pitched sounds
Outer Hair cells nearest the Oval Window specifically detect high pitched
sounds
Inner Hair Cells nearest the Helicotrema specifically detect low pitched
sounds
Outer Hair cells specifically detect the loudness of a sound
Inner Hair cells specifically detect the loudness of a sound
5. Explain how the opening of Cl- channels contributes to the generation of an
inhibitory postsynaptic potential in a neuron.
It depolarizes the neuron, making it more likely to fire an action
potential.
It hyperpolarizes the neuron, making it less likely to fire an action
potential.
It has no effect on the neuron's ability to fire an action potential.
It increases the overall excitability of the neuron.
6. Explain the significance of a motor unit in muscle contraction and how it relates
to muscle strength.
A) Motor units are irrelevant to muscle contraction strength.
B) A motor unit consists of multiple motor axons, which increases
strength.
C) The size and number of motor units recruited determine the
strength of muscle contraction.
D) Motor units only function during voluntary muscle contractions.
E) Motor units are only involved in reflex actions.
,7. If a drug were developed that selectively inhibited the G proteins associated
with metabotropic receptors, what effect would you expect this to have on
neurotransmission?
Increased speed of synaptic transmission due to enhanced ion channel
opening.
Decreased synaptic plasticity and modulation of neurotransmitter
effects.
Enhanced activation of ionotropic receptors.
No effect on neurotransmitter binding to receptors.
Increased production of second messengers.
8. Contrary to popular belief, cone cells do not detect a single color of light but
rather a spectrum of light that has a peak. The three types of cones can be more
accurately described as:
Short, medium and long wavelength
Cyan, magenta and yellow
Sharp, medium and low acuity
A-type, B-type and C-type
9. Which of the following statements about color vision is false?
Absorption spectra of cone cells varies due to molecular differences
in the 11-cis-retinal molecules.
There are three different types of cone cells in the human retina.
Rods do not contribute to color vision.
Rhodopsins in the human retina differ in the range of wavelengths of light
they absorb best.
Birds have four classes of cone cells.
, 10. Which protein does myosin specifically bind to during muscle
contraction?
Calcium
Actin
Troponin
Myoglobin
11. Explain the role of cone cells in the human visual system and how they differ
from rod cells in terms of color detection.
Cone cells detect light intensity, while rod cells detect color.
Cone cells are responsible for color vision, while rod cells are
sensitive to low light levels.
Both cone and rod cells detect color equally.
Rod cells are more concentrated in the fovea than cone cells.
12. Predict Question: What effect will the increased stimulus intensity have on the
frequency of action potential?
the frequency of action potential will decrease.
the frequency of action potential will remain the same.
the frequency of action potential will increase.
13. Range fractionation in sensory physiology refers to
The different modalities to which sensory receptors respond
The range of stimulus intensity to which a single receptor cell for a
certain modality responds
The division of a modality range into subunits among many
receptors of a population of receptors
Qs & Ans ( PDF) | Graded A+
1. If a neuron is stimulated experimentally at both ends simultaneously to
generate action potentials, what would you expect to happen?
the two action potentials will meet in the middle and die off.
on meeting together, they will both travel towards the axon terminals.
stronger action potential will override the weaker one and travel to the
opposite side.
the two action potentials will meet in the middle and continue traveling to
the other side.
2. Temporal summation of postsynaptic potentials _____
occurs when a single neuron releases a neurotransmitter more than
once and in rapid succession
occurs because of the convergence of many neurons on a single postsynaptic
cell
only involves excitatory postsynaptic potentials
only involves inhibitory postsynaptic potentials
3. Which type of cells are responsible for the formation of myelin sheaths in the
central nervous system (CNS)?
Schwann cells
oligodendrocytes
astrocytes
microglia
,4. Which of the following CORRECTLY explains how cells of the inner ear
detect sound?
Every Hair cell detects high and low pitched sounds
Outer Hair cells nearest the Oval Window specifically detect high pitched
sounds
Inner Hair Cells nearest the Helicotrema specifically detect low pitched
sounds
Outer Hair cells specifically detect the loudness of a sound
Inner Hair cells specifically detect the loudness of a sound
5. Explain how the opening of Cl- channels contributes to the generation of an
inhibitory postsynaptic potential in a neuron.
It depolarizes the neuron, making it more likely to fire an action
potential.
It hyperpolarizes the neuron, making it less likely to fire an action
potential.
It has no effect on the neuron's ability to fire an action potential.
It increases the overall excitability of the neuron.
6. Explain the significance of a motor unit in muscle contraction and how it relates
to muscle strength.
A) Motor units are irrelevant to muscle contraction strength.
B) A motor unit consists of multiple motor axons, which increases
strength.
C) The size and number of motor units recruited determine the
strength of muscle contraction.
D) Motor units only function during voluntary muscle contractions.
E) Motor units are only involved in reflex actions.
,7. If a drug were developed that selectively inhibited the G proteins associated
with metabotropic receptors, what effect would you expect this to have on
neurotransmission?
Increased speed of synaptic transmission due to enhanced ion channel
opening.
Decreased synaptic plasticity and modulation of neurotransmitter
effects.
Enhanced activation of ionotropic receptors.
No effect on neurotransmitter binding to receptors.
Increased production of second messengers.
8. Contrary to popular belief, cone cells do not detect a single color of light but
rather a spectrum of light that has a peak. The three types of cones can be more
accurately described as:
Short, medium and long wavelength
Cyan, magenta and yellow
Sharp, medium and low acuity
A-type, B-type and C-type
9. Which of the following statements about color vision is false?
Absorption spectra of cone cells varies due to molecular differences
in the 11-cis-retinal molecules.
There are three different types of cone cells in the human retina.
Rods do not contribute to color vision.
Rhodopsins in the human retina differ in the range of wavelengths of light
they absorb best.
Birds have four classes of cone cells.
, 10. Which protein does myosin specifically bind to during muscle
contraction?
Calcium
Actin
Troponin
Myoglobin
11. Explain the role of cone cells in the human visual system and how they differ
from rod cells in terms of color detection.
Cone cells detect light intensity, while rod cells detect color.
Cone cells are responsible for color vision, while rod cells are
sensitive to low light levels.
Both cone and rod cells detect color equally.
Rod cells are more concentrated in the fovea than cone cells.
12. Predict Question: What effect will the increased stimulus intensity have on the
frequency of action potential?
the frequency of action potential will decrease.
the frequency of action potential will remain the same.
the frequency of action potential will increase.
13. Range fractionation in sensory physiology refers to
The different modalities to which sensory receptors respond
The range of stimulus intensity to which a single receptor cell for a
certain modality responds
The division of a modality range into subunits among many
receptors of a population of receptors
