Question 1

According to the _____ law, a neuron fires an action potential at only one level of intensity.
A)all-or-none
B)threshold
C)refractory
D)action

Accepted Answer

The all-or-none law states that a neuron either fires an action potential at a full response or does not fire at all, depending on whether the stimulus reaches the threshold level.

Question 2

In addition to other roles, acetylcholine appears to be involved in attention, arousal, learning, and memory, and its degeneration related to Alzheimer's disease. In what brain structure would you expect to find a high percentage of acetylcholine receptors?
A)Pons
B)H ypothalamus
C)Hippocampus
D)Thalamus

Accepted Answer

The hippocampus is a critical brain structure involved in learning and memory, processes that heavily rely on acetylcholine. Degeneration of acetylcholine-producing neurons in Alzheimer's disease significantly affects the hippocampus, leading to memory loss and cognitive decline.

Question 3

The microscopic gap between the terminal buttons of one neuron and the cell membrane of another neuron is the ​
A)neurotransmitter cleft.
B)synaptic cleft.
C)presynaptic space.
D)postsynaptic space.

Accepted Answer

The correct term for the microscopic gap between the terminal buttons of one neuron and the cell membrane of another neuron is the "synaptic cleft." This space facilitates the transmission of neurotransmitters from one neuron to another.

Question 4

Dr. Jacoby has just discovered a new drug that blocks the action of acetylcholine. This new drug will likely produce side effects such as
A)general stimulation within the body and an increase in heart rate.
B)paralysis and memory loss.
C)anxiety reduction and general relaxation.
D)hallucinations and disrupted sleep patterns.

Accepted Answer

Blocking the action of acetylcholine can lead to paralysis because acetylcholine is crucial for muscle activation. Memory loss can occur since acetylcholine is also involved in learning and memory processes.

Question 5

Reabsorption of neurotransmitters into the presynaptic neuron is referred to as ​
A)cyclomyosis.
B)regrading.
C)uploading.
D)reuptake.

Accepted Answer

Reuptake is the process by which neurotransmitters are taken back into the presynaptic neuron after being released into the synaptic cleft, allowing them to be reused.

Question 6

The neurons in Michael's arm just sent a neural impulse. It will be 1-2 milliseconds before another neural impulse can be generated. This brief time period, when another neural impulse cannot occur, is called the ​
A)all-or-none period.
B)absolute refractory period.
C)resting potential.
D)postsynaptic discharge.

Accepted Answer

The absolute refractory period is the brief time after an action potential during which a neuron cannot generate another action potential, regardless of the strength of the stimulus. This is due to the inactivation of sodium channels, which are necessary for the initiation of an action potential.

Question 7

Sara is holding Scott's hand during a scary movie. Suddenly, she squeezes his hand very hard. When she does this, the neurons in Scott's hand will ​
A)start to fire at a faster rate.
B)send stronger signals to his central nervous system.
C)enter an absolute refractory period.
D)release more chloride ions.

Accepted Answer

When Sara squeezes Scott's hand hard, the neurons in his hand will fire at a faster rate to signal the increased pressure to the central nervous system.

Question 8

The minimum length of time between action potentials is determined by
A)transduction capacity.
B)transduction incapacity.
C)the absolute refractory period.
D)the relative threshold period.

Accepted Answer

The absolute refractory period is the minimum length of time after an action potential during which another action potential cannot begin, thus determining the minimum interval between action potentials.

Question 9

The elimination of old, less active synapses is known as ​
A)synaptic reuptake.
B)synaptic pruning.
C)neurogenesis.
D)synaptic sculpting.

Accepted Answer

Synaptic pruning is the process by which extra neurons and synaptic connections are eliminated in order to increase the efficiency of neuronal transmissions.

Question 10

Synaptic vesicles are structures that ​
A)control the speed with which a neuron fires.
B)manufacture myelin.
C)store neurotransmitters.
D)provide energy for a neuron's activity.

Accepted Answer

Synaptic vesicles are specialized organelles within neurons that store neurotransmitters, which are chemicals used by neurons to communicate with each other at synapses.

Question 11

Fiona puts her hands into a sink of lukewarm water; Luke puts his hands into a sink of ice-cold water. Based on what is known about neural transmission, you could predict that the action potentials will ​
A)travel more quickly in Luke's system because the stimulus is more intense.
B)be weaker in Fiona's system because the stimulus is less intense.
C)be the same in both individuals due to the all-or-none principle.
D)travel a shorter distance in Luke's system because the stimulus is more intense.

Accepted Answer

The all-or-none principle states that once an action potential is triggered in a neuron, it travels down the axon without decreasing in strength, regardless of the stimulus intensity. Thus, the action potentials in both Fiona and Luke's systems would be the same.

Question 12

The release of neurotransmitters into the synaptic cleft is caused by the arrival of the
A)action potential at the postsynaptic neuron.
B)resting potential at the postsynaptic neuron.
C)action potential at the terminal buttons.
D)resting potential at the terminal buttons.

Accepted Answer

The release of neurotransmitters into the synaptic cleft is triggered by the arrival of an action potential at the terminal buttons (or axon terminals) of the presynaptic neuron. This causes the vesicles containing neurotransmitters to fuse with the presynaptic membrane and release their contents into the synaptic cleft.

Question 13

Leonard's mother became dehydrated during a recent illness, and the levels of sodium in her body were significantly reduced. If enough sodium was lost, you might expect that ​
A)her nervous system would become highly activated and action potentials would be generated continuously.
B)fewer action potentials would occur in her nervous system.
C)more neurotransmitters would be produced in her terminal buttons.
D)glial cells would start to degenerate and die.

Accepted Answer

Sodium ions play a crucial role in generating action potentials in neurons. A significant reduction in sodium levels would impair the ability of neurons to generate these action potentials, leading to decreased neural activity.

Question 14

A postsynaptic potential occurs when ​
A)neurotransmitters are released into the synaptic cleft.
B)neurotransmitters are reabsorbed into the terminal buttons.
C)neurotransmitters bind or attach to receptor sites on the postsynaptic neuron.
D)neurotransmitters bind or attach to receptor sites on the presynaptic neuron.

Accepted Answer

A postsynaptic potential occurs when neurotransmitters bind or attach to receptor sites on the postsynaptic neuron, leading to changes in the membrane potential of the postsynaptic cell.

Question 15

If inhibitory postsynaptic potentials did not exist, ​
A)it would be "easier" for a neuron to fire its action potential.
B)it would be "harder" for a neuron to fire its action potential.
C)there would not be any effect on the ease at which a neuron fires its action potential.
D)it would be impossible for neural impulses to travel across the synapse.

Accepted Answer

Inhibitory postsynaptic potentials (IPSPs) serve to decrease the likelihood that a neuron will fire an action potential by making the inside of the neuron more negatively charged compared to the outside. Without IPSPs, there would be less inhibition, making it easier for a neuron to reach the threshold needed to fire an action potential.

Question 16

Jeremy is sitting quietly when the muscles in his left leg begin to "twitch." This activation of movement in his voluntary muscles is MOST likely due to the release of the neurotransmitter
A)serotonin.
B)dopamine.
C)acetylcholine.
D)norepinephrine.

Accepted Answer

Acetylcholine is the primary neurotransmitter responsible for muscle activation in the peripheral nervous system. It is released at the neuromuscular junction and binds to receptors on muscle cells, causing them to contract or "twitch."

Question 17

During an action potential, the neuron's electrical charge is ​
A)negative and travels along the axon.
B)negative and travels along the dendrite.
C)positive and travels along the axon.
D)positive and travels along the dendrite.

Accepted Answer

During an action potential, the neuron's electrical charge becomes positive due to the influx of sodium ions, and this change in charge travels along the axon, not the dendrite.

Question 18

An electric potential that increases the likelihood that the postsynaptic neuron will fire is called an ​
A)all-or-none potential.
B)inhibitory postsynaptic potential.
C)excitatory postsynaptic potential.
D)excitatory presynaptic potential.

Accepted Answer

An excitatory postsynaptic potential (EPSP) is a synaptic potential that makes a neuron more likely to fire an action potential. This is typically achieved by the neurotransmitter-induced depolarization of the postsynaptic membrane, making the neuron's internal environment less negative and closer to the threshold for firing an action potential.

Question 19

An impulse moves from one neuron to another through the action of ​
A)neurotransmitters.
B)hormones.
C)action potentials.
D)neuromodulators.

Accepted Answer

Neurotransmitters are chemicals that allow neurons to communicate with each other across synapses, facilitating the transmission of impulses from one neuron to another.

Question 20

Peggy smells a very strong odor; Harry smells an odor that is barely detectable. Based on what is known about neural transmission, you could predict that the action potentials will
A)travel more quickly in Peggy's system because the stimulus is more intense.
B)be weaker in Harry's system because the stimulus is less intense.
C)travel a shorter distance in Peggy's system because the stimulus is more intense.
D)fire more rapidly in Peggy's system because of the stronger stimulus.

Accepted Answer

Action potentials do not vary in strength or speed based on the intensity of the stimulus; instead, the frequency of action potentials increases with stronger stimuli. Thus, a stronger odor would cause action potentials to fire more rapidly in Peggy's system.

Quiz 3: The Biological Bases of Behavior

According to the _____ law, a neuron fires an action potential at only one level of intensity.

In addition to other roles, acetylcholine appears to be involved in attention, arousal, learning, and memory, and its degeneration related to Alzheimer's disease. In what brain structure would you expect to find a high percentage of acetylcholine receptors?

The microscopic gap between the terminal buttons of one neuron and the cell membrane of another neuron is the ​

Dr. Jacoby has just discovered a new drug that blocks the action of acetylcholine. This new drug will likely produce side effects such as

Reabsorption of neurotransmitters into the presynaptic neuron is referred to as ​

The neurons in Michael's arm just sent a neural impulse. It will be 1-2 milliseconds before another neural impulse can be generated. This brief time period, when another neural impulse cannot occur, is called the ​

Sara is holding Scott's hand during a scary movie. Suddenly, she squeezes his hand very hard. When she does this, the neurons in Scott's hand will ​

The minimum length of time between action potentials is determined by

The elimination of old, less active synapses is known as ​

Synaptic vesicles are structures that ​

Fiona puts her hands into a sink of lukewarm water; Luke puts his hands into a sink of ice-cold water. Based on what is known about neural transmission, you could predict that the action potentials will ​

The release of neurotransmitters into the synaptic cleft is caused by the arrival of the

Leonard's mother became dehydrated during a recent illness, and the levels of sodium in her body were significantly reduced. If enough sodium was lost, you might expect that ​

A postsynaptic potential occurs when ​

If inhibitory postsynaptic potentials did not exist, ​

Jeremy is sitting quietly when the muscles in his left leg begin to "twitch." This activation of movement in his voluntary muscles is MOST likely due to the release of the neurotransmitter

During an action potential, the neuron's electrical charge is ​

An electric potential that increases the likelihood that the postsynaptic neuron will fire is called an ​

An impulse moves from one neuron to another through the action of ​

Peggy smells a very strong odor; Harry smells an odor that is barely detectable. Based on what is known about neural transmission, you could predict that the action potentials will

The microscopic gap between the terminal buttons of one neuron and the cell membrane of another neuron is the

Reabsorption of neurotransmitters into the presynaptic neuron is referred to as

The neurons in Michael's arm just sent a neural impulse. It will be 1-2 milliseconds before another neural impulse can be generated. This brief time period, when another neural impulse cannot occur, is called the

Sara is holding Scott's hand during a scary movie. Suddenly, she squeezes his hand very hard. When she does this, the neurons in Scott's hand will

The elimination of old, less active synapses is known as

Synaptic vesicles are structures that

Fiona puts her hands into a sink of lukewarm water; Luke puts his hands into a sink of ice-cold water. Based on what is known about neural transmission, you could predict that the action potentials will

Leonard's mother became dehydrated during a recent illness, and the levels of sodium in her body were significantly reduced. If enough sodium was lost, you might expect that

A postsynaptic potential occurs when

If inhibitory postsynaptic potentials did not exist,

During an action potential, the neuron's electrical charge is

An electric potential that increases the likelihood that the postsynaptic neuron will fire is called an

An impulse moves from one neuron to another through the action of