Question 1

The primary neurotransmitter from the parasympathetic system that influences its autonomic targets is

Accepted Answer

A) acetylcholine. 
B) adenosine. 
C) norepinephrine. 
D) adrenaline. 
E) dopamine. 
A) acetylcholine. 
B) adenosine. 
C) norepinephrine. 
D) adrenaline. 
E) dopamine.

Question 2

The surface on a neuron that discharges synaptic vesicles is the

Accepted Answer

A) dendrite. 
B) axon hillock. 
C) node of Ranvier. 
D) postsynaptic membrane. 
E) presynaptic membrane. 
A) dendrite. 
B) axon hillock. 
C) node of Ranvier. 
D) postsynaptic membrane. 
E) presynaptic membrane.

Question 3

Neurotransmitters are released from axon terminals via

Accepted Answer

A) osmosis. 
B) active transport. 
C) diffusion. 
D) transcytosis. 
E) exocytosis. 
A) osmosis. 
B) active transport. 
C) diffusion. 
D) transcytosis. 
E) exocytosis.

Question 4

The activity of acetylcholine in a synapse is terminated by

Accepted Answer

A) its active transport across the presynaptic membrane. 
B) its diffusion across the presynaptic membrane. 
C) its active transport across the postsynaptic membrane. 
D) its diffusion across the postsynaptic membrane. 
E) its degradation by a hydrolytic enzyme on the postsynaptic membrane. 
A) its active transport across the presynaptic membrane. 
B) its diffusion across the presynaptic membrane. 
C) its active transport across the postsynaptic membrane. 
D) its diffusion across the postsynaptic membrane. 
E) its degradation by a hydrolytic enzyme on the postsynaptic membrane.

Question 5

One disadvantage to a nerve net is that it can 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 6

The "selectivity" of a particular ion channel refers to its

Accepted Answer

A) permitting passage by positive but not negative ions. 
B) permitting passage by negative but not positive ions. 
C) ability to change its size depending on the ion needing transport. 
D) binding with only one type of neurotransmitter. 
E) permitting passage only to a specific ion. 
A) permitting passage by positive but not negative ions. 
B) permitting passage by negative but not positive ions. 
C) ability to change its size depending on the ion needing transport. 
D) binding with only one type of neurotransmitter. 
E) permitting passage only to a specific ion.

Question 7

Assume that a single IPSP has a negative magnitude of - 0.5 mV at the axon hillock, and that a single EPSP has a positive magnitude of + 0.5 mV. For a neuron with initial membrane potential is -70 mV, the net effect of the simultaneous arrival of 6 IPSPs and 2 EPSPs would be to move the membrane potential to

Accepted Answer

A) -72 mV. 
B) -71 mV. 
C) -70 mV. 
D) -69 mV. 
E) -68 mV. 
A) -72 mV. 
B) -71 mV. 
C) -70 mV. 
D) -69 mV. 
E) -68 mV.

Question 8

Most of the organelles in a neuron are located in the

Accepted Answer

A) dendritic region. 
B) axon hillock. 
C) axon. 
D) cell body. 
E) axon terminals. 
A) dendritic region. 
B) axon hillock. 
C) axon. 
D) cell body. 
E) axon terminals.

Question 9

In the communication link between a motor neuron and a skeletal muscle,

Accepted Answer

A) the motor neuron is considered the presynaptic cell and the skeletal muscle is the postsynaptic cell. 
B) the motor neuron is considered the postsynaptic cell and the skeletal muscle is the presynaptic cell. 
C) action potentials are possible on the motor neuron but not the skeletal muscle. 
D) action potentials are possible on the skeletal muscle but not the motor neuron. 
E) the motor neuron fires action potentials but the skeletal muscle is not electrochemically excitable. 
A) the motor neuron is considered the presynaptic cell and the skeletal muscle is the postsynaptic cell. 
B) the motor neuron is considered the postsynaptic cell and the skeletal muscle is the presynaptic cell. 
C) action potentials are possible on the motor neuron but not the skeletal muscle. 
D) action potentials are possible on the skeletal muscle but not the motor neuron. 
E) the motor neuron fires action potentials but the skeletal muscle is not electrochemically excitable.

Question 10

A "resting" motor neuron is expected to

Accepted Answer

A) releases lots of acetylcholine. 
B) to have high permeability to sodium ions. 
C) to 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 the cell than on the outside. 
A) releases lots of acetylcholine. 
B) to have high permeability to sodium ions. 
C) to 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 the cell than on the outside.

Question 11

Neurotransmitters categorized as inhibitory would 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.

Question 12

The observation that the acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it is an example of

Accepted Answer

A) a voltage-gated sodium channel. 
B) a voltage-gated potassium channel. 
C) a ligand-gated sodium channel. 
D) a second-messenger-gated sodium channel. 
E) a chemical that inhibits action potentials. 
A) a voltage-gated sodium channel. 
B) a voltage-gated potassium channel. 
C) a ligand-gated sodium channel. 
D) a second-messenger-gated sodium channel. 
E) a chemical that inhibits action potentials.

Question 13

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 14

Where are neurotransmitter receptors located?

Accepted Answer

A) on the nuclear membrane 
B) at nodes of Ranvier 
C) on the postsynaptic membrane 
D) on the membranes of synaptic vesicles 
E) in the myelin sheath 
A) on the nuclear membrane 
B) at nodes of Ranvier 
C) on the postsynaptic membrane 
D) on the membranes of synaptic vesicles 
E) in the myelin sheath

Question 15

This neuro-active compound is not stored in presynaptic vesicles:

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

The steps below refer to various stages in transmission at a chemical synapse: 1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.
2) Calcium ions rush into neuron's cytoplasm.
3) An action potential depolarizes the membrane of the axon terminal.
4) The ligand-gated ion channels open.
5) The synaptic vesicles release neurotransmitter into the synaptic cleft.
Which sequence of events is correct?

Accepted Answer

A) 1 → 2 → 3 → 4 → 5 
B) 2 → 3 → 5 → 4 → 1 
C) 3 → 2 → 5 → 1 → 4 
D) 4 → 3 → 1 → 2 → 5 
E) 5 → 1 → 2 → 4 → 3 
A) 1 → 2 → 3 → 4 → 5 
B) 2 → 3 → 5 → 4 → 1 
C) 3 → 2 → 5 → 1 → 4 
D) 4 → 3 → 1 → 2 → 5 
E) 5 → 1 → 2 → 4 → 3

Question 17

Why are action potentials usually conducted in only one direction along an axon?

Accepted Answer

A) The nodes of Ranvier can conduct potentials in only one direction. 
B) The brief refractory period prevents reopening of voltage-gated Na+ channels. 
C) The axon hillock has a higher membrane potential than the terminals of the axon. 
D) Ions can flow along the axon in only one direction. 
E) Voltage-gated channels for both Na+ and K+ open in only one direction. 
A) The nodes of Ranvier can conduct potentials in only one direction. 
B) The brief refractory period prevents reopening of voltage-gated Na+ channels. 
C) The axon hillock has a higher membrane potential than the terminals of the axon. 
D) Ions can flow along the axon in only one direction. 
E) Voltage-gated channels for both Na+ and K+ open in only one direction.

Question 18

What happens when a 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 becomes less likely to generate an action potential. 
E) The inside of the cell becomes more negative relative to 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 becomes less likely to generate an action potential. 
E) The inside of the cell becomes more negative relative to the outside.

Question 19

Temporal summation always involves

Accepted Answer

A) both inhibitory and excitatory inputs. 
B) synapses at more than one site. 
C) inputs that are not simultaneous. 
D) electrical synapses. 
E) myelinated axons. 
A) both inhibitory and excitatory inputs. 
B) synapses at more than one site. 
C) inputs that are not simultaneous. 
D) electrical synapses. 
E) myelinated axons.

Question 20

For the following questions, refer to the graph of an action potential in Figure 48.1 and use the letters to indicate your answer.
   
Figure 48.1
-The membrane potential is closest to the equilibrium potential for potassium at label

Accepted Answer

The answer of For the following questions, refer to the...

Exam 48: Neurons, Synapses, and Signaling

The primary neurotransmitter from the parasympathetic system that influences its autonomic targets is

The surface on a neuron that discharges synaptic vesicles is the

Neurotransmitters are released from axon terminals via

The activity of acetylcholine in a synapse is terminated by

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

The "selectivity" of a particular ion channel refers to its

Most of the organelles in a neuron are located in the

In the communication link between a motor neuron and a skeletal muscle,

A "resting" motor neuron is expected to

Neurotransmitters categorized as inhibitory would are expected to

The observation that the acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it is an example of

The operation of the sodium-potassium "pump" moves

Where are neurotransmitter receptors located?

This neuro-active compound is not stored in presynaptic vesicles:

Why are action potentials usually conducted in only one direction along an axon?

What happens when a neuron's membrane depolarizes?

Temporal summation always involves

For the following questions, refer to the graph of an action potential in Figure 48.1 and use the letters to indicate your answer. Figure 48.1 -The membrane potential is closest to the equilibrium potential for potassium at label

Introduction: Themes in the Study of Life

The Chemical Context of Life

Water and the Fitness of the Environment

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: Harvesting Chemical Energy

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

Control of Gene Expression

Viruses

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 Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure, Growth, and Development

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 Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems

Conservation Biology and Restoration Ecology

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