AP Psychology : Biology

Study concepts, example questions & explanations for AP Psychology

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Example Questions

Example Question #151 : Biology And Sensation

Which of the following best describes how neurotransmitters in the synapse can be deactivated?

Possible Answers:

Benzodiazepines

Reuptake 

Reuptake and chemical breakdown by enzymes

Benzodiazepines and chemical breakdown by enzymes

Chemical breakdown by enzymes

Correct answer:

Reuptake and chemical breakdown by enzymes

Explanation:

Reuptake is reabsorption of neurotransmitter into the neuron. Chemically breaking down neurotransmitters makes them nonfunctional.

Example Question #152 : Biology And Sensation

Where are neurotransmitters stored in the axon terminal?

Possible Answers:

Cell body

Dendrites

Synaptic vesicles

Receptors

Synapses

Correct answer:

Synaptic vesicles

Explanation:

Synaptic vesicles are at the end of the presynaptic neuron, and they release neurotransmitter into the synapse. Dendrites are outer branched extensions of a neuron. Synapses are the structures that permit neuron transfer.

Example Question #31 : Neurons And Action Potentials

Which of the following best describes the junction where information is transmitted from one neuron to another?

Possible Answers:

None of these

Myelin sheath

Terminal buttons

Synapse

Correct answer:

Synapse

Explanation:

The synapse is the place where two neurons meet to transmit information. In other words, in between two neurons is the synapse, sometimes called the "synaptic gap". Terminal buttons are at the end of each axon and they secrete neurotransmitters. They are very close to the synapse, but not the right answer in this case. The myelin sheath encases the axon in order to insulate the cell, which speeds up the transmission of signals.

Example Question #32 : Neurons And Action Potentials

When a neuron's electrical charge suddenly shifts from negative to positive, it creates a(n) __________

Possible Answers:

New neuron

Synaptic cleft

Refractory period

Action potential

Correct answer:

Action potential

Explanation:

An action potential is a very brief shift or spike in a neuron's electrical charge that sends a message down the axon. An action potential is the can be described as a neuron "firing.” Action potentials occur after the resting potential and before a refractory period.

The synaptic cleft is the microscopic gap between neurons. The refractory period is a very brief period of time after an action potential in which another action potential cannot begin. One can think of the refractory period like a very brief rest period.

Example Question #31 : Neurons And Action Potentials

__________ are individual cells in the nervous system that receive, integrate, and transmit information. 

Possible Answers:

Dendrites

Neurotransmitters

Hormones

Neurons

Correct answer:

Neurons

Explanation:

Neurons—also called nerve cells—are the basic links that allow communication within the nervous system. Neurotransmitters are chemical messengers that activate neighboring neurons, but they are not cells. Dendrites are part of a neuron—they are the branchy parts of the neuron that are specialized to receive incoming information. Hormones are also a type of chemical messenger; however, they are transmitted by the circulatory system and not the nervous system. 

Example Question #36 : Neurons And Action Potentials

Which of the following best explains how one neuron transmits a signal to another neuron?

Possible Answers:

The first neuron releases synaptic vesicles, which burst when they come into contact with the second neuron, releasing neurotransmitters onto its surface.

The first neuron releases neurotransmitters directly into the cell body of the second neuron.

Signals are not transmitted from one neuron to another.

The first neuron releases neurotransmitters into the synaptic cleft and the neurotransmitters bind to the receptors of the second neuron.

The electrical charge from the action potential of the first neuron spreads to the neuron that it is connected to.

Correct answer:

The first neuron releases neurotransmitters into the synaptic cleft and the neurotransmitters bind to the receptors of the second neuron.

Explanation:

The axon terminal of a neuron contains synaptic vesicles containing neurotransmitters. After an action potential, neurotransmitters are released and diffuse across the synaptic cleft, where they bind to receptors on the dendrites of another neuron. This can cause an action potential in the second neuron. Neurons are not directly connected to each other. Synaptic vesicles do not exist outside of the cell body.

Example Question #31 : Neurons And Action Potentials

__________ receive messages from other neurons. Sufficient levels of stimulation trigger the cell’s own __________, sending an electrical current down the __________ to the cell’s __________, which join with yet more cells.

 

Possible Answers:

Axons. . . signal. . . myelin sheath. . . terminal buttons

Dendrites. . . neurotransmitter. . . axon. . . nerve ending

Neurotransmitters. . . signal. . . myelin sheath. . . dendrites

Dendrites. . . action potential. . . axon. . . terminal buttons

Correct answer:

Dendrites. . . action potential. . . axon. . . terminal buttons

Explanation:

Nerve cells, or neurons, have a basic tree-like structure, which allows them to communicate with other nerve cells. Branch-like dendrites extend from the cell body (i.e. soma) and receive electrochemical signals from other cells. The long, thin axon endings—terminal buttons—extend from the other end of the soma. If the positively-charged signals received into the cell from the dendrites exceed the cell’s normally negative charge, then the axon allows the excess positive ions to travel down it to the terminal buttons, which in turn send neurotransmitters into the gap (i.e. synapse) between them and other cell’s dendrites. The myelin sheath does not itself relay signals, but rather is a natural lipid insulation on the axons of some cells. 

Example Question #31 : Neurons And Action Potentials

Which of the following ions are involved with electrical transmission within neurons?

Possible Answers:

Sodium and calcium

Potassium and calcium 

Sodium and oxygen 

Sodium and chloride 

Sodium and potassium

Correct answer:

Sodium and potassium

Explanation:

Sodium and potassium are vital components associated with neural electrical transmissions. When it is at rest, a neuron is surrounded by a positive charge due to sodium and maintains an internally negative charge with potassium. When the neuron depolarizes, there is an influx of sodium into the cell. Upon repolarization, there is a potassium efflux where the neuron is restored to its original resting charges.

Example Question #31 : Neurons And Action Potentials

A certain medication, atropine, binds to receptor sites intended for acetylcholine. It effectively blocks these receptor sites, but does not trigger the associated neuron to fire. Based on this information, atropine's relationship to acetylcholine is best described as which of the following?

Possible Answers:

Antagonist

Reuptake agent

Agonist

Neurotransmitter

Correct answer:

Antagonist

Explanation:

The correct answer is antagonist. An antagonist is any chemical that prevents a neurotransmitter from binding to its receptor site. Recall that a neurotransmitter is simply any chemical in the brain that enables the transmission of signals between neurons via synapses. Contrastingly, an agonist is any chemical that mimics the shape of a neurotransmitter well enough that it can bind to that neurotransmitter's receptor and stimulate the receptor just as if the neurotransmitter itself was binding to it. A so-called reuptake agent is not a real chemical classification, but the reuptake mechanism is an important aspect of neurotransmission. Reuptake refers to the process by which the presynaptic neuron reabsorbs its released neurotransmitter after the neurotransmitter has done its job by binding to the postsynaptic neuron.

Example Question #31 : Neurons And Action Potentials

Which of the following best identifies the order that signals propagate through the components of a neuron?

Possible Answers:

Axon, cell body, dendrites, terminal buttons

Dendrites, axon, cell body, terminal buttons

Cell body, axon, dendrites, terminal buttons

Terminal buttons, dendrites, axon, cell body

Dendrites, cell Body, axon, terminal buttons

Correct answer:

Dendrites, cell Body, axon, terminal buttons

Explanation:

Information enters the neuron through dendrites, the branch-like extensions which carry signals to the cell body (soma). When an action potential occurs, its signal will propagate down the axon of the cell, culminating in the release of neurotransmitters into the synapse from the terminal buttons. These neurotransmitters will cross the synaptic cleft in mere milliseconds, and bind to the receptor sites on the adjacent neuron's dendrites. This process leads to communication between neurons.

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