Question 1

Adjacent neurons with direct (non-neurotransmitter)action potential transfer are said to have electrical synapses, based on the presence of

Accepted Answer

A) tight junctions at their point of contact. 
B) gap junctions at their point of contact. 
C) leaky junctions at their point of contact. 
D) anchoring junctions at their point of contact. 
E) desmosomes at their point of contact. 
A) tight junctions at their point of contact. 
B) gap junctions at their point of contact. 
C) leaky junctions at their point of contact. 
D) anchoring junctions at their point of contact. 
E) desmosomes at their point of contact. B

Question 2

Use the following information to answer the next few questions.
The baseball career of Lou Gehrig, a first baseman for the New York Yankees, ended once he became afflicted with amyotrophic lateral sclerosis (ALS). This disease causes the degeneration of motor neurons in the CNS, leading to rapidly progressive weakness, muscle spasticity, and atrophy. Research into the disease has shown that individuals with ALS have higher levels of the neurotransmitter glutamate in their serum and spinal fluid when compared to normal individuals.
-Riluzole, an approved drug for ALS, blocks glutamate transporters, which inhibits the activation of

Accepted Answer

A) voltage-gated ion channels. 
B) ligand-gated channels. 
C) stretch-activated ion channels. 
D) temperature-gated channels. 
E) mechanosensitive ion channels. 
A) voltage-gated ion channels. 
B) ligand-gated channels. 
C) stretch-activated ion channels. 
D) temperature-gated channels. 
E) mechanosensitive ion channels. B

Question 3

Neurotransmitters categorized as inhibitory are expected to

Accepted Answer

A) act independently of their receptor proteins. 
B) close potassium channels. 
C) open sodium channels. 
D) close chloride channels. 
E) hyperpolarize the membrane. 
A) act independently of their receptor proteins. 
B) close potassium channels. 
C) open sodium channels. 
D) close chloride channels. 
E) hyperpolarize the membrane. E

Question 4

A "resting" motor neuron is expected to

Accepted Answer

A) release lots of acetylcholine. 
B) have high permeability to sodium ions. 
C) be equally permeable to sodium and potassium ions. 
D) exhibit a resting potential that is more negative than the "threshold" potential. 
E) have a higher concentration of sodium ions on the inside of the cell than on the outside. 
A) release lots of acetylcholine. 
B) have high permeability to sodium ions. 
C) be equally permeable to sodium and potassium ions. 
D) exhibit a resting potential that is more negative than the "threshold" potential. 
E) have a higher concentration of sodium ions on the inside of the cell than on the outside.

Question 5

For the following questions, refer to the graph of an action potential.
  
-The neuronal membrane is at its resting potential at label

Accepted Answer

A) A. 
B) B. 
C) C. 
D) D. 
E) E. 
A) A. 
B) B. 
C) C. 
D) D. 
E) E.

Question 6

An example of ligand-gated ion channels is

Accepted Answer

A) the spreading of action potentials in the heart. 
B) acetylcholine receptors at the neuromuscular junction. 
C) cAMP-dependent protein kinases. 
D) action potentials on the axon. 
E) graded hyperpolarization. 
A) the spreading of action potentials in the heart. 
B) acetylcholine receptors at the neuromuscular junction. 
C) cAMP-dependent protein kinases. 
D) action potentials on the axon. 
E) graded hyperpolarization.

Question 7

In the sequence of permeability changes for a complete action potential, the first of these events that occurs is

Accepted Answer

A) the activation of the sodium-potassium "pump." 
B) the inhibition of the sodium-potassium "pump." 
C) the opening of voltage-gated sodium channels. 
D) the closing of voltage-gated potassium channels. 
E) the opening of voltage-gated potassium channels. 
A) the activation of the sodium-potassium "pump." 
B) the inhibition of the sodium-potassium "pump." 
C) the opening of voltage-gated sodium channels. 
D) the closing of voltage-gated potassium channels. 
E) the opening of voltage-gated potassium channels.

Question 8

Use the following information to answer the next few questions.
The baseball career of Lou Gehrig, a first baseman for the New York Yankees, ended once he became afflicted with amyotrophic lateral sclerosis (ALS). This disease causes the degeneration of motor neurons in the CNS, leading to rapidly progressive weakness, muscle spasticity, and atrophy. Research into the disease has shown that individuals with ALS have higher levels of the neurotransmitter glutamate in their serum and spinal fluid when compared to normal individuals.
-What happens when a resting neuron's membrane depolarizes?

Accepted Answer

A) There is a net diffusion of Na⁺ out of the cell. 
B) The equilibrium potential for K⁺ (EK)becomes more positive. 
C) The neuron's membrane voltage becomes more positive. 
D) The neuron is less likely to generate an action potential. 
E) The cell's inside is more negative than the outside. 
A) There is a net diffusion of Na⁺ out of the cell. 
B) The equilibrium potential for K⁺ (EK)becomes more positive. 
C) The neuron's membrane voltage becomes more positive. 
D) The neuron is less likely to generate an action potential. 
E) The cell's inside is more negative than the outside.

Question 9

Upon pricking your finger with a pin, which of the following variables change during the conduction of the produced action potential?

Accepted Answer

A) magnitude 
B) frequency 
C) duration 
D) amplitude 
E) threshold 
A) magnitude 
B) frequency 
C) duration 
D) amplitude 
E) threshold

Question 10

When several IPSPs arrive at the axon hillock rapidly in sequence from a single dendritic location, hyperpolarizing the postsynaptic cell more and more and thus preventing an action potential, this is an example of

Accepted Answer

A) temporal summation. 
B) spatial summation. 
C) tetanus. 
D) the refractory state. 
E) an action potential with an abnormally high peak of depolarization. 
A) temporal summation. 
B) spatial summation. 
C) tetanus. 
D) the refractory state. 
E) an action potential with an abnormally high peak of depolarization.

Question 11

In certain large animals, this type of neuron can extend beyond 1 metre in length.

Accepted Answer

A) glial cell in the brain 
B) a sensory neuron 
C) an interneuron 
D) a glial cell at a ganglion 
E) a neuron that controls eye movements 
A) glial cell in the brain 
B) a sensory neuron 
C) an interneuron 
D) a glial cell at a ganglion 
E) a neuron that controls eye movements

Question 12

Neurotransmitters affect postsynaptic cells by

Accepted Answer

A) initiating signal transduction pathways in the cells. 
B) causing molecular changes in the cells. 
C) affecting ion-channel proteins. 
D) altering the permeability of the cells. 
E) All of these options are correct. 
A) initiating signal transduction pathways in the cells. 
B) causing molecular changes in the cells. 
C) affecting ion-channel proteins. 
D) altering the permeability of the cells. 
E) All of these options are correct.

Question 13

The major excitatory neurotransmitter of the human brain is

Accepted Answer

A) acetylcholine. 
B) epinephrine. 
C) glutamate. 
D) nitric oxide. 
E) GABA. 
A) acetylcholine. 
B) epinephrine. 
C) glutamate. 
D) nitric oxide. 
E) GABA.

Question 14

One possible disadvantage to a nerve net is that it might conduct impulses in two directions from the point of the stimulus. Most of the synapses in vertebrates conduct information in only one direction

Accepted Answer

A) as a result of the nodes of Ranvier. 
B) as a result of voltage-gated sodium channels found only in the vertebrate system. 
C) because vertebrate nerve cells have dendrites. 
D) because only the postsynaptic cells can bind and respond to neurotransmitters. 
E) because the sodium-potassium pump moves ions in one direction. 
A) as a result of the nodes of Ranvier. 
B) as a result of voltage-gated sodium channels found only in the vertebrate system. 
C) because vertebrate nerve cells have dendrites. 
D) because only the postsynaptic cells can bind and respond to neurotransmitters. 
E) because the sodium-potassium pump moves ions in one direction.

Question 15

An amino acid that operates at inhibitory synapses in the brain is

Accepted Answer

A) acetylcholine. 
B) epinephrine. 
C) endorphin. 
D) nitric oxide. 
E) GABA. 
A) acetylcholine. 
B) epinephrine. 
C) endorphin. 
D) nitric oxide. 
E) GABA.

Question 16

A graded hyperpolarization of a membrane can be induced by

Accepted Answer

A) increasing its membrane's permeability to Na⁺. 
B) decreasing its membrane's permeability to H⁺. 
C) decreasing its membrane's permeability to Cl⁻. 
D) increasing its membrane's permeability to Ca⁺⁺. 
E) increasing its membrane's permeability to K⁺. 
A) increasing its membrane's permeability to Na⁺. 
B) decreasing its membrane's permeability to H⁺. 
C) decreasing its membrane's permeability to Cl⁻. 
D) increasing its membrane's permeability to Ca⁺⁺. 
E) increasing its membrane's permeability to K⁺.

Question 17

The operation of the sodium-potassium "pump" moves

Accepted Answer

A) sodium and potassium ions into the cell. 
B) sodium and potassium ions out of the cell. 
C) sodium ions into the cell and potassium ions out of the cell. 
D) sodium ions out of the cell and potassium ions into the cell. 
E) sodium and potassium ions into the mitochondria. 
A) sodium and potassium ions into the cell. 
B) sodium and potassium ions out of the cell. 
C) sodium ions into the cell and potassium ions out of the cell. 
D) sodium ions out of the cell and potassium ions into the cell. 
E) sodium and potassium ions into the mitochondria.

Question 18

Opening all of the sodium channels, with all other ion channels closed-which is an admittedly artificial setting-on an otherwise typical neuron should move its membrane potential to

Accepted Answer

A) -90 mV. 
B) -70 mV. 
C) 0 mV. 
D) +30 mV. 
E) +62 mV. 
A) -90 mV. 
B) -70 mV. 
C) 0 mV. 
D) +30 mV. 
E) +62 mV.

Question 19

After the depolarization phase of an action potential, the resting potential is restored by

Accepted Answer

A) the opening of sodium activation gates. 
B) the opening of voltage-gated potassium channels and the closing of sodium channels. 
C) a decrease in the membrane's permeability to potassium and chloride ions. 
D) a brief inhibition of the sodium-potassium pump. 
E) the opening of more voltage-gated sodium channels. 
A) the opening of sodium activation gates. 
B) the opening of voltage-gated potassium channels and the closing of sodium channels. 
C) a decrease in the membrane's permeability to potassium and chloride ions. 
D) a brief inhibition of the sodium-potassium pump. 
E) the opening of more voltage-gated sodium channels.

Question 20

The membrane potential that exactly offsets an ion's concentration gradient is called the

Accepted Answer

A) graded potential. 
B) threshold potential. 
C) equilibrium potential. 
D) action potential. 
E) inhibitory postsynaptic potential. 
A) graded potential. 
B) threshold potential. 
C) equilibrium potential. 
D) action potential. 
E) inhibitory postsynaptic potential.

Exam 48: Neurons, Synapses, and Signalling

Adjacent neurons with direct (non-neurotransmitter)action potential transfer are said to have electrical synapses, based on the presence of

Neurotransmitters categorized as inhibitory are expected to

A "resting" motor neuron is expected to

For the following questions, refer to the graph of an action potential. -The neuronal membrane is at its resting potential at label

An example of ligand-gated ion channels is

In the sequence of permeability changes for a complete action potential, the first of these events that occurs is

Upon pricking your finger with a pin, which of the following variables change during the conduction of the produced action potential?

When several IPSPs arrive at the axon hillock rapidly in sequence from a single dendritic location, hyperpolarizing the postsynaptic cell more and more and thus preventing an action potential, this is an example of

In certain large animals, this type of neuron can extend beyond 1 metre in length.

Neurotransmitters affect postsynaptic cells by

The major excitatory neurotransmitter of the human brain is

One possible disadvantage to a nerve net is that it might conduct impulses in two directions from the point of the stimulus. Most of the synapses in vertebrates conduct information in only one direction

An amino acid that operates at inhibitory synapses in the brain is

A graded hyperpolarization of a membrane can be induced by

The operation of the sodium-potassium "pump" moves

Opening all of the sodium channels, with all other ion channels closed-which is an admittedly artificial setting-on an otherwise typical neuron should move its membrane potential to

After the depolarization phase of an action potential, the resting potential is restored by

The membrane potential that exactly offsets an ion's concentration gradient is called the

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

Dna Tools and Biotechnology

Genomes and Their Evolution

Descent With Modification: a Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity Ii: the Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

Filters