Deck 34: Neurons, Sense Organs, and Nervous Systems

Question 1

A current in a living cell is based on

A) a flow of electrons.
B) a flow of ions in aqueous solution.
C) a flow of ions in membrane lipids.
D) attractions among positive ions.
E) attractions among negative ions.

Answer 1

B

Question 2

Which statement about myelin is false?

A) It is conductive.
B) It is lipid-rich.
C) It insulates the axon.
D) It is made of glial cell membranes.
E) It appears white and glistening.

Answer 2

A

Question 3

The four functional regions of a typical neuron include all of the following except the

A) axon.
B) synaptic cleft.
C) cell body.
D) dendrites
E) presynaptic axon terminals.

Answer 3

B

Question 4

If the resting potential of the neuronal cell membrane is between -60 and -70 mV,the cell

A) is -60 to -70 mV more negative inside than outside.
B) is -60 to -70 mV more positive inside than outside.
C) has a potential of -60 to -70 mV on both sides of the membrane.
D) must build up a potential of -60 to -70 mV inside the cell before it can carry an action potential.
E) must build up a potential of -60 to -70 mV outside the cell before it can carry an action potential.

Question 5

What is the difference between glial cells and neurons?

A) Glial cells nourish and support neurons.
B) A neuron is the body of a glial cell.
C) Glial cells include parts of multiple neurons.
D) Glial cells carry information away from the brain;neurons carry it to the brain.
E) There is no difference;neurons and glial cells are the same type of cell.

Question 6

What is the difference between a nerve and a neuron?

A) A neuron is the body of a nerve.
B) Nerves nourish and support neurons.
C) A nerve is a bundle of axons from multiple neurons.
D) Nerves carry information away from the brain;neurons carry it to the brain.
E) There is no difference;the terms describe the same structure.

Question 7

A certain cell is highly elongated and is able to conduct an action potential to a specific location.It is also able to integrate signals from many other cells into a single output.This type of cell is a(n)

A) neuron.
B) glial cell.
C) muscle cell.
D) oligodendrocyte.
E) Schwann cell.

Question 8

A neuron is said to be "addressed" because it is able to

A) carry an impulse very rapidly.
B) carry an impulse long distances.
C) travel in more than one direction.
D) convey impulses to a specific location in the CNS.
E) receive communications from other cells.

Question 9

If a star-nosed mole lost the use of its star-shaped sensory organ,it would be unable to find food by

A) smelling.
B) touching.
C) tasting.
D) seeing.
E) hearing.

Question 10

A neuron that is not connected to a postsynaptic cell will be unable to

A) conduct a nerve impulse down its axon.
B) receive a nerve impulse.
C) undergo depolarization.
D) receive nourishment from a glial cell.
E) send a nerve impulse to another neuron.

Question 11

Nervous systems are composed of which two primary cell types?

A) Neurons and glial cells
B) Neurons and epithelial cells
C) Fibroblasts and chondrocytes
D) Epithelial cells and glandular cells
E) Neuromuscular cells and epithelial cells

Question 12

A cell membrane has an electrical polarity in which the outside is more negative than the inside.This cell membrane is

A) depolarized and conducting an impulse.
B) polarized and conducting an impulse.
C) polarized and not conducting an impulse.
D) depolarized and not conducting an impulse.
E) repolarizing after conducting an impulse.

Question 13

A voltage is a(n)

A) action potential.
B) electrical potential difference.
C) flow of electrically charged particles.
D) electrical difference within a bulk solution.
E) electrical difference within mixed positive and negative charges.

Question 14

The region where two neurons come into close contact with each other and pass along information is a(n)

A) axon.
B) dendrite.
C) synapse.
D) cell body.
E) glial cell.

Question 15

Besides neurons,which other type of cell is excitable?

A) Glial cells
B) Blood cells
C) Muscle cells
D) Secretory cells
E) Epithelial cells

Question 16

An axon travels from the spinal cord to the legs.It is surrounded by a concentric ring of lipid-rich cell membrane that insulates the axon and speeds up its transmission of electrical impulses.This covering is composed of

A) synapses.
B) dendrites.
C) Schwann cells.
D) nodes of Ranvier.
E) oligodendrocytes.

Question 17

Which of the following is not a function of glial cells?

A) Supplying nutrients
B) Insulating nerve tissue
C) Conducting nerve impulses
D) Consuming foreign particles
E) Orienting neurons during embryonic development

Question 18

The function of combining and integrating incoming signals into a single output occurs in which part of the neuron?

A) Axon
B) Dendrites
C) Cell body and axon hillock
D) Presynaptic axon terminals
E) Postsynaptic axon terminals

Question 19

A potential difference can build up across a cell membrane,but not in a bulk solution inside the cell,because

A) lipids in the cell membrane are hydrophobic and prevent ions from crossing.
B) lipids in the cell membrane capture ions and prevent them from crossing.
C) proteins in the cell membrane capture ions and prevent them from crossing.
D) proteins in the cell membrane are hydrophobic and prevent ions from crossing.
E) there is no way to move ions from one side of a membrane to the other side.

Question 20

While you read this question,your neurons send information to and from your brain;meanwhile,the metabolic needs of those neurons are assisted by

A) synapses.
B) glial cells.
C) excitable cells.
D) Schwann cells.
E) oligodendrocytes.

Question 21

The major cause of the resting potential is the cell membrane's

A) negative ion pump.
B) open K⁺ ion channels.
C) sodium‒potassium pump.
D) voltage-gated ion channels.
E) stretch-gated ion channels.

Question 22

In the saltatory conduction of action potentials,the nerve impulses jump from one node of Ranvier to another.This occurs because

A) only the nodes contain neurotransmitters.
B) the nodes are very well insulated and conduct impulses rapidly.
C) jumping from node to node prevents the impulse from traveling backward.
D) jumping from node to node ensures that the impulse travels slowly and evenly.
E) the membrane regions between nodes are well insulated and cannot conduct electrical impulses.

Question 23

The most rapid conduction of an action potential will occur in an axon of which type?

A) Small and myelinated
B) Small and unmyelinated
C) Large and myelinated
D) Large and unmyelinated
E) Any size and myelinated

Question 24

Na⁺ channels in a membrane open,allowing sodium ions to diffuse into a neuron.The membrane potential changes from -70 mV to -65 mV.This membrane response can best be described as

A) equilibrium.
B) hyperpolarization.
C) graded depolarization.
D) all-or-none depolarization.
E) the generation of an action potential.

Question 25

Refer to the diagram below.This diagram illustrates the generating of an action potential by a process of

A) positive feedback.
B) negative feedback.
C) neuron deactivation.
D) neuron repolarization.
E) chemical transmission.

Question 26

A nerve cell body is able to depolarize within only one millisecond because,when the threshold potential is reached,

A) the entire length of the membrane is affected at once.
B) large numbers of voltage-gated K⁺ channels open very quickly.
C) large numbers of voltage-gated Na⁺ channels open very quickly.
D) only a very small electrical change is needed to reverse polarity.
E) only a single signal is usually required to cause depolarization.

Question 27

Which of these is not a characteristic of an action potential?

A) It lasts approximately one millisecond.
B) It decreases in size as it moves down the axon.
C) It is localized in one region of the neuron membrane at any given moment.
D) It causes a reversal of polarity in the neuron membrane.
E) It propagates along the axon when each axonal region stimulates the next.

Question 28

The Nernst equation calculates the membrane equilibrium potential to be approximately -80 mV,which is slightly different from the measured resting neuron potential of -60 to -70 mV.The difference most likely occurs because

A) the membrane equilibrium potential is not a resting potential.
B) the equation assumes only one ion (K⁺)can move across the membrane.
C) the equation assumes only one ion (Na⁺)can move across the membrane.
D) the sodium‒potassium pump works differently in neurons than in other cells.
E) the temperature of cells is different from the temperature used in the equation.

Question 29

How do graded changes in membrane potential give rise to all-or-none changes that generate action potentials?

A) The membrane recognizes only action potentials generated by positive ions,causing a voltage threshold to be reached.
B) The membrane recognizes only action potentials generated by negative ions,causing a voltage threshold to be reached.
C) Many graded potentials at different points along the membrane are summed,causing the voltage threshold to be reached.
D) Many graded potentials reaching the same point on the membrane are summed,causing the voltage threshold to be reached.
E) The membrane allows only voltage-gated channels to open and close,enabling an electrical charge gradient to be created.

Question 30

Which statement about Na⁺-K⁺-ATPase is false?

A) It is a transporter protein.
B) It is a membrane protein.
C) It is a membrane enzyme.
D) It is a sodium‒chloride pump.
E) It is a sodium‒potassium pump.

Question 31

If ATP was not available to run the cell's sodium-potassium pump,which function would stop?

A) Leakage of K⁺ ions into the cell
B) Leakage of K⁺ ions out of the cell
C) Active transport of K⁺ to the outside of the cell
D) Active transport of Na⁺ to the inside of the cell
E) Active transport of Na⁺ to the outside of the cell

Question 32

Sodium (Na⁺)is unable to cross a membrane until a local change in the membrane potential occurs.This suggests that Na⁺ transfer across membranes is controlled by a(n)

A) voltage-gated ion channel.
B) ligand-gated ion channel.
C) stretch-gated ion channel.
D) ion channel that is always open.
E) ion channel that is always closed.

Question 33

In which organism are you likely to find myelinated axons?

A) Squid
B) Insect
C) Sea slug
D) Dolphin
E) Earthworm

Question 34

A cell membrane can undergo a rapid change from the resting potential to carrying an action potential.Which process enables this change?

A) Lipids in the cell membrane allow a few positive ions to move into the cell.
B) Lipids in the cell membrane allow many positive ions to move into the cell.
C) An ion channel protein allows a few positive ions to move into the cell.
D) An ion channel protein allows very large numbers of positive ions to move into the cell.
E) An ion channel protein floods the entire bulk solution in the cell with positive ions.

Question 35

An action potential is generated when sufficient incoming signals are received by the dendrites to reach threshold.This action potential occurs at the _______ region of the neuron and results from the _______ of the signals.

A) dendritic;spreading
B) cell body;spreading
C) cell body;integration
D) axon hillock;integration
E) presynaptic axon terminal;transmission

Question 36

Suppose an ion channel opens and allows the influx of chloride (Cl^-),a negative ion,into a cell.Which change would occur in the cell membrane?

A) Equilibrium
B) Hyperpolarization
C) Graded depolarization
D) All-or-none depolarization
E) Generation of an action potential

Question 37

Which statement accurately describes an action potential?

A) Its magnitude increases along the axon.
B) Its magnitude decreases along the axon.
C) All action potentials in a single neuron are of the same magnitude.
D) During an action potential,the membrane potential of a neuron remains constant.
E) An action potential permanently shifts a neuron's membrane potential away from its resting value.

Question 38

Compared to a graded potential,an action potential is _______ and _______.

A) larger;is an all-or-none event
B) smaller;is an all-or-none event
C) larger;can have a range of values
D) smaller;can have a range of values
E) larger;does not propagate along the axon

Question 39

Following depolarization,which action is required to restore,or repolarize,the neural membrane potential?

A) A Na⁺-K⁺ pump returns ions to their original concentrations.
B) The neuron membrane becomes freely permeable to many ions.
C) Cl^- channels open and Cl^- ions rush inward through the membrane.
D) Na⁺ channels open and Na⁺ ions rush outward through the membrane.
E) K⁺ channels open and K⁺ ions rush outward through the membrane.

Question 40

If only the K⁺ ion channels in a cell membrane are open,the cell membrane will move toward a(n)

A) resting potential.
B) action potential.
C) equilibrium potential for K⁺.
D) equilibrium potential for Na⁺.
E) equilibrium of both K⁺ and Na⁺.

Question 41

Adaptations such as myelinated axons and axons with large diameters would be most useful for which type of organisms?

A) Sedentary animals
B) Slow-moving burrowers
C) Animals with toxic stings
D) Animals with protective shells
E) Fast-moving predator or prey animals

Question 42

Which conditions would most likely have led to the evolution of electrical synapses rather than chemical synapses in a species?

A) Conditions that require thinking
B) Conditions that require rapid escape
C) Conditions that require repetitive motion
D) Any conditions;electrical synapses are faster,so they are always more adaptive.
E) Any conditions;electrical synapses are stronger,so they are always more adaptive.

Question 43

After a neurotransmitter diffuses across the synaptic cleft,what is the next action that occurs in transmission of an action potential?

A) Neurotransmitter molecules immediately depolarize the postsynaptic membrane.
B) Neurotransmitter molecules bind to receptor proteins in the postsynaptic membrane.
C) A delay occurs while receptor proteins are synthesized in the postsynaptic membrane.
D) A delay occurs while neurotransmitter molecules are transformed into ions that carry the action potential.
E) A single neurotransmitter molecule immediately triggers an action potential in the postsynaptic membrane.

Question 44

The most common type of interconnection between two neurons in the nervous system is a(n)

A) motor end-plate.
B) chemical synapse.
C) electrical synapse.
D) neuromuscular junction.
E) direct connection between cells.

Question 45

What determines the function carried out by a neurotransmitter at a neuron-to-neuron synapse?

A) The type of neurotransmitter released
B) The strength of the action potential generated
C) The type of receptor binding the neurotransmitter
D) The number of neurotransmitter molecules released
E) The rate at which neurotransmitter molecules are released

Question 46

Which type of neurotransmitter is released at the neuromuscular junction of vertebrates?

A) Dopamine
B) Serotonin
C) Glutamate
D) Acetylcholine
E) Norepinephrine

Question 47

The vertebrate neuromuscular junction has often been used as a model for understanding the functioning of a synapse because it

A) involves only one neuron and one muscle cell.
B) operates in the same way as synapses in the brain do.
C) uses acetylcholine,the only well-understood neurotransmitter.
D) can be used to understand both chemical and electrical synapses.
E) has a measurable action potential,unlike neuron-to-neuron synapses.

Question 48

For summation of membrane potentials and subsequent generation of an action potential to occur,all incoming synaptic potentials must

A) be excitatory (EPSPs).
B) be inhibitory (IPSPs).
C) originate at the same time and place.
D) originate from the same place,although they may occur at separate times.
E) originate at the same time,although they may come from separate places.

Question 49

After neurotransmitter molecules travel across the synaptic cleft and bind to receptors on the postsynaptic cell,remaining molecules in the synaptic cleft are removed rapidly.If the molecules were not removed,transmission of information would most likely

A) continue at the same rate.
B) continue and become faster and faster.
C) continue and become stronger and stronger.
D) stop,because no information is arriving at the nerve terminal.
E) stop,because the membrane would lose its responsiveness.

Question 50

A series of steps occurs between the arrival of an action potential at a presynaptic axon terminal and the initiation of an action potential in the postsynaptic neuron.What is the last step in this process?

A) Opening of Ca²⁺ channels in the presynaptic membrane
B) Fusing of synaptic vesicles with the presynaptic membrane
C) Spreading of depolarization to neighboring regions of the postsynaptic membrane
D) Influx of Na⁺,causing a graded depolarization of the postsynaptic membrane
E) Binding of acetylcholine to gated receptor proteins,allowing diffusion of Na⁺ and K⁺

Question 51

Suppose an action potential arrives at the axon terminal but the voltage-gated calcium channels at the terminal fail to open.What will most likely happen to the action potential?

A) It will stop,because Ca²⁺ will not enter the presynaptic cell and the neurotransmitter will not be released.
B) It will stop,because Ca²⁺ will not be available to act as a neurotransmitter in place of acetylcholine.
C) It will continue,because Ca²⁺ will be released by an electrical method and the neurotransmitter will be released.
D) It will continue,because although the neurotransmitter will not be released,Na⁺ and K⁺ will be released in the postsynaptic membrane.
E) It will continue,because although Ca²⁺ will not be released,synaptic vesicles will use another method to fuse with the presynaptic membrane.

Question 52

Which characteristic would best indicate that a particular synapse is a neuron-to-neuron synapse and not a neuromuscular junction?

A) All impulses reaching the postsynaptic cell are inhibitory.
B) All impulses reaching the postsynaptic cell are excitatory.
C) A single nerve impulse from the presynaptic cell generates an action potential.
D) An action potential results from many small signals received over a long time period.
E) An action potential results from the summation of many small signals received in a short amount of time.

Question 53

Which statement about a metabotropic neurotransmitter receptor is true?

A) It is a ligand-gated ion channel.
B) It is a voltage-gated ion channel.
C) It has a single,very specific effect on a cell.
D) It often controls production of second messengers.
E) It causes a very rapid,short-lived change in the membrane.

Question 54

When an action potential arrives at an axon terminal,it causes the opening of _______ channels,which triggers fusion of neurotransmitter vesicles with the cell membrane.

A) sodium
B) chloride
C) calcium
D) potassium
E) acetylcholine

Question 55

At an electrical synapse,how is the action potential able to move from one neuron to the next?

A) The neuron cell membranes are connected by gap junctions.
B) A neurotransmitter carries the action potential across the synaptic cleft.
C) The electrical charge of the action potential jumps across the synaptic cleft.
D) A neurotransmitter binds to the postsynaptic neuron and generates a new action potential.
E) The electrical charge of the action potential bypasses presynaptic boutons and directly enters the synaptic cleft.

Question 56

A neurotransmitter receptor is a ligand-gated ion channel,and neurotransmitter binding to this receptor results in a rapid but short-lived change in the postsynaptic membrane potential.This type of receptor is most likely

A) synaptic.
B) excitatory.
C) inhibitory.
D) ionotropic.
E) metabotropic.

Question 57

In transmission of information in the nervous system,what is one way in which the process differs if a neuron,rather than a muscle fiber,serves as the postsynaptic cell?

A) All responses are excitatory.
B) All responses are fast and short-lived.
C) There may be hundreds or thousands of presynaptic cells.
D) The presynaptic cell always releases serotonin rather than acetylcholine.
E) The same receptors are used,regardless of the neurotransmitter released.

Question 58

After a neurotransmitter such as acetylcholine or glutamate enters a synaptic cleft,several things can happen to it.Which of these does not happen to a neurotransmitter during normal nervous system activity?

A) It remains in the synaptic cleft.
B) It is taken up by a nearby neuron.
C) It is taken up by a nearby glial cell.
D) It is taken up again by the presynaptic neuron.
E) It is broken down in the synaptic cleft by enzymes.

Question 59

In a situation that requires the most rapid possible response as an action potential crosses the synaptic cleft,_______ provide fast,invariant signal transmission.

A) motor end-plates
B) nodes of Ranvier
C) chemical synapses
D) electrical synapses
E) neuromuscular junctions

Question 60

Which step is not part of the sequence of events that triggers synaptic transmission from a neuron to a muscle fiber?

A) Entry of Ca²⁺ into the presynaptic terminal
B) Release of norepinephrine into the synaptic cleft
C) Opening of Ca²⁺ channels in the presynaptic terminal
D) Arrival of an action potential at the presynaptic terminal
E) Fusion of synaptic vesicles with the presynaptic membrane

Question 61

A male insect's body contains neurons that detect tiny concentrations of pheromones,or attractant molecules secreted by the female insect.The neurons change these chemical signals into electrical signals.Would these neurons be considered sensory receptor neurons?

A) Yes,because they receive and transform sensory information.
B) Yes,because they are neurons.
C) No,because they detect only tiny differences in the environment.
D) No,because they are present only in male insects.
E) No,because they receive chemical signals,not light or sound.

Question 62

A birdwatcher who is learning to identify a new bird notes the bird's color pattern,its call,and its name.Each time she sees the new bird,she becomes more efficient at identifying it.In regard to underlying synaptic plasticity,which action is likely occurring in the birdwatcher's brain?

A) Repeated stimulation of the same synapses
B) Repeated stimulation of unrelated synapses
C) Stimulation of a single type of synapse
D) Release of a new kind of neurotransmitter
E) Continued response to a dangerous situation

Question 63

A person who suddenly smells an extremely strong,offensive odor is able to perceive it as strong because of the

A) offensiveness of the odor.
B) strength of each action potential.
C) brain location to which the stimulus goes.
D) frequency of action potentials reaching the brain.
E) suddenness with which the stimulus was perceived.

Question 64

Stretch-gated Na⁺ ion channel receptors are of most use in which type of sensory receptor cell?

A) Visual sensor
B) Muscle sensor
C) Taste sensor
D) Olfactory sensor
E) Temperature sensor

Question 65

Brushing against a doorway as you enter a room will trigger which type of sensory response?

A) Metabotropic
B) Chemoreceptor
C) Thermoreceptor
D) Mechanoreceptor
E) Second messenger cascade

Question 66

Synaptic plasticity is thought to underlie which brain function?

A) Emotions
B) Locomotion
C) Instinctive behavior
D) Learning and memory
E) Sensory functions,such as sight

Question 67

Sneezing normally occurs when irritation in the nasal cavity sends a signal through the ophthalmic branch of the trigeminal nerve to the brainstem.When a person sneezes in bright sunlight,what is most likely happening in the person's sensory system?

A) Stimulation of sensory receptors in the eye sends impulses to the visual cortex.
B) Stimulation of sensory receptors in the nasal cavity sends impulses to the visual cortex.
C) Stimulation of sensory receptors in the eye sends impulses to the trigeminal nerve and brainstem.
D) Stimulation of sensory receptors in the nasal cavity sends impulses to the trigeminal nerve and brainstem.
E) Stimulation of the optic nerve triggers action potentials in the nearby trigeminal nerve,which sends impulses to the brainstem.

Question 68

All sensory information enters the brain in the form of electrical impulses,or action potentials.The brain determines the source of the sensory information based on the

A) pattern of the signals.
B) strength of the signals.
C) frequency of the signals.
D) time at which the signals arrive.
E) location at which the signals arrive.

Question 69

Assume that several thousand presynaptic neurons synapse with a single postsynaptic neuron.The various presynaptic neurons release ten different neurotransmitters,which are bound by specific (and varying)receptors on the postsynaptic neuron.For an action potential to be generated in the postsynaptic neuron,what must occur?

A) All neurotransmitter receptors must be ionotropic.
B) All neurotransmitter receptors must be metabotropic.
C) All postsynaptic potentials must be greater than the threshold potential.
D) There must be more IPSPs than EPSPs occurring at the same time and place.
E) The postsynaptic potentials occurring at a single time must sum to a value greater than the threshold potential.

Question 70

A sensory receptor cell is specific to only one kind of stimulus because it

A) encounters only one kind of stimulus.
B) has one specific type of receptor protein.
C) is located in a specific part of the body.
D) has only one type of cell membrane structure.
E) can only form a specific kind of action potential.

Question 71

Which statement about sensory receptor cells is false?

A) They are modified neurons.
B) They generate action potentials.
C) They carry out sensory transduction.
D) They respond to any type of stimulus.
E) They are specific for only one type of stimulus.

Question 72

Transduction of information in sensory receptor cells results in a change from

A) stimulus energy to electrical energy.
B) electrical energy to stimulus energy.
C) a physical form to a chemical form.
D) an action potential to a synaptic signal.
E) a high-energy form to a low-energy form.

Question 73

Which type of sensory receptor is not an ionotropic receptor?

A) Touch receptor
B) Stretch receptor
C) Pressure receptor
D) Olfactory receptor
E) Heat and cold receptor

Question 74

Which of the following best represents the order of the flow of information from a muscle in a crayfish that will ultimately generate an action potential in the crayfish stretch receptor neuron?

A) Stretch,stretch-gated Na⁺ channels open,receptor potential,voltage-gated Na⁺ channels open,action potential
B) Stretch,dendritic potential,stretch-gated Na⁺ channels open,receptor potential,action potential
C) Stretch,receptor potential,spread of potential in receptor neuron,neurotransmitter release,action potential
D) Stretch,neurotransmitter release,receptor potential,stretch-gated Na⁺ channels open,action potential
E) Stretch,neurotransmitter release,stretch-gated Na⁺ channels open,voltage-gated Na⁺ channels open,action potential

Question 75

Whether a synapse is excitatory or inhibitory depends on the

A) size of the synapse.
B) presynaptic axon terminal.
C) type of neurotransmitter.
D) nature of the postsynaptic receptors.
E) concentration of neurotransmitter in the synaptic space.

Question 76

An animal's sensory processes enable it to detect and respond to

A) its external environment only.
B) its internal physical status only.
C) both internal and external environmental factors.
D) only information entering the body in electrical form.
E) only information relating to the typical "five senses."

Question 77

The olfactory apparatus of mammals includes highly folded microvilli and cilia within the nasal region.What is the likely purpose of this greatly increased surface area?

A) To concentrate sensory receptor cells into a small area
B) To increase the mammal's sensitivity to olfactory stimuli
C) To make room for other types of sensory cells in this area
D) To shorten the distance between the stimulus and the brain
E) To provide the space needed for larger metabotropic sensory cells

Question 78

The difference between an IPSP and an EPSP is that an EPSP produces

A) membrane depolarization and makes an action potential less likely.
B) membrane depolarization and makes an action potential more likely.
C) membrane hyperpolarization and makes an action potential less likely.
D) membrane hyperpolarization and makes an action potential more likely.
E) graded membrane depolarization,while an IPSP produces an all-or-none response.

Question 79

Compared to an ionotropic receptor cell,a metabotropic receptor cell is more likely to have a

A) greater sensitivity to stimuli.
B) larger membrane surface area.
C) ligand-gated Na⁺ channel receptor protein.
D) receptor protein that is a G protein or activates one.
E) receptor protein that always directly generates an action potential.

Question 80

Increase in which neural response is not likely to be due to short-term synaptic plasticity?

A) Growth in size of synapses
B) Number of IPSPs at a synapse
C) Number of receptors at a synapse
D) Quantity of neurotransmitters released
E) Ability of cells to respond to a neurotransmitter