Question 1

The resting membrane potential in animal cells depends largely on nongated _____ channels.

Accepted Answer

A) Ca²⁺ 
B) H⁺ 
C) K⁺ 
D) Na⁺ 
A) Ca²⁺ 
B) H⁺ 
C) K⁺ 
D) Na⁺ C

Question 2

Fruit flies carrying the shaker mutation have motor neurons with an abnormally long action potential because of:

Accepted Answer

A) a defect in the Na⁺/K⁺ pump. 
B) a defect in voltage-gated Na⁺ channels. 
C) a defect in non-voltage-gated K⁺ channels. 
D) a defect in voltage-gated K⁺ channels. 
A) a defect in the Na⁺/K⁺ pump. 
B) a defect in voltage-gated Na⁺ channels. 
C) a defect in non-voltage-gated K⁺ channels. 
D) a defect in voltage-gated K⁺ channels. D

Question 3

How do researchers measure ion movements through single channels?

Accepted Answer

Patch clamping is a technique that measures the electric current caused by the movement of ions across a small patch of the plasma membrane.The membrane is electrically depolarized or hyperpolarized and maintained (clamped)at that potential by an electronic feedback device.The inward or outward movement of ions across a patch of membrane can be quantified from the amount of electric current needed to maintain the membrane potential at the designated "clamped" value.

Question 4

During the development of specialized postsynaptic structures at a neuromuscular junction,preexisting AChR proteins on the surface of the uninnervated muscle are induced to aggregate by:

Accepted Answer

A) agrin,a signal released from the neuron. 
B) the muscle membrane protein,MuSK. 
C) the cytosolic protein,rapsyn. 
D) all of the above 
A) agrin,a signal released from the neuron. 
B) the muscle membrane protein,MuSK. 
C) the cytosolic protein,rapsyn. 
D) all of the above

Question 5

How are most voltage-gated channels inactivated?

Accepted Answer

A) by ligand binding 
B) by changes in membrane potential 
C) through interaction with other membrane proteins 
D) by closing spontaneously soon after opening 
A) by ligand binding 
B) by changes in membrane potential 
C) through interaction with other membrane proteins 
D) by closing spontaneously soon after opening

Question 6

Signaling at synapses is usually terminated by:

Accepted Answer

A) calcium influx. 
B) potassium influx. 
C) inhibitory neurotransmitters. 
D) degradation or reuptake of neurotransmitters. 
A) calcium influx. 
B) potassium influx. 
C) inhibitory neurotransmitters. 
D) degradation or reuptake of neurotransmitters.

Question 7

Neurotransmitters are stored in:

Accepted Answer

A) the cell body. 
B) the dendrite. 
C) the axon hillock. 
D) synaptic vesicles. 
A) the cell body. 
B) the dendrite. 
C) the axon hillock. 
D) synaptic vesicles.

Question 8

Reception of taste causes:

Accepted Answer

A) an action potential that travels along the axon of a taste cell. 
B) release of neurotransmitters that are detected by adjacent neurons. 
C) an increase in cGMP that inactivates ligand gated Na⁺/Ca⁺² channels. 
D) activation of TRPV1,which is a ligand gated Na⁺/Ca⁺² channel. 
A) an action potential that travels along the axon of a taste cell. 
B) release of neurotransmitters that are detected by adjacent neurons. 
C) an increase in cGMP that inactivates ligand gated Na⁺/Ca⁺² channels. 
D) activation of TRPV1,which is a ligand gated Na⁺/Ca⁺² channel.

Question 9

Repolarization during the refractory period is largely due to the:

Accepted Answer

A) opening of non-voltage-gated K⁺ channels. 
B) opening of voltage-gated K⁺ channels. 
C) opening of voltage-gated Na⁺ channels. 
D) action of the Na⁺/K⁺ pump. 
A) opening of non-voltage-gated K⁺ channels. 
B) opening of voltage-gated K⁺ channels. 
C) opening of voltage-gated Na⁺ channels. 
D) action of the Na⁺/K⁺ pump.

Question 10

How does opening and closing of voltage-gated cation channels occur?

Accepted Answer

All voltage-gated ion channels have simi

Question 11

Evidence that synaptotagmin is the Ca²⁺ sensor for exocytosis of neurotransmitters includes:

Accepted Answer

A) Ca²⁺ binding by synaptotagmin. 
B) partial loss-of-function mutations of synaptotagmin in Drosophila and C.elegans that result in neurons that are defective in Ca²⁺-stimulated vesicle exocytosis. 
C) uncoordinated embryonic muscle contractions in Drosophila and c.elegans mutants that lack synaptotagmin. 
D) all of the above 
A) Ca²⁺ binding by synaptotagmin. 
B) partial loss-of-function mutations of synaptotagmin in Drosophila and C.elegans that result in neurons that are defective in Ca²⁺-stimulated vesicle exocytosis. 
C) uncoordinated embryonic muscle contractions in Drosophila and c.elegans mutants that lack synaptotagmin. 
D) all of the above

Question 12

Touch receptors are:

Accepted Answer

A) non-gated cation channels. 
B) gated cation channels. 
C) calcium ion pumps. 
D) G protein-coupled receptors. 
A) non-gated cation channels. 
B) gated cation channels. 
C) calcium ion pumps. 
D) G protein-coupled receptors.

Question 13

Action potentials are propagated in only one direction,down the axon.Explain how the absolute refractory period of the voltage-gated Na⁺ channels and the brief hyperpolarization resulting from K⁺ efflux produces this outcome.

Accepted Answer

The Na⁺ influx due to opening of the vol

Question 14

What starts an action potential in a post-synaptic neuron?

Accepted Answer

When an action potential reaches the ter

Question 15

How does the nicotinic acetylcholine receptor function as a ligand-gated ion channel at nerve-muscle synapses?

Accepted Answer

The nicotinic acetylcholine receptor is

Question 16

In a human brain,the number of glial cells is:

Accepted Answer

A) about 1/10 the number of neurons. 
B) about the same as the number of neurons. 
C) about 10 times the number of neurons. 
D) about 100-200 times the number of neurons. 
A) about 1/10 the number of neurons. 
B) about the same as the number of neurons. 
C) about 10 times the number of neurons. 
D) about 100-200 times the number of neurons.

Question 17

The birth of new neurons in the adult brain occurs in:

Accepted Answer

A) the dentate gyrus. 
B) the brainstem. 
C) olfactory bulb. 
D) neural tube. 
A) the dentate gyrus. 
B) the brainstem. 
C) olfactory bulb. 
D) neural tube.

Question 18

During an action potential,which happens first?

Accepted Answer

A) opening of voltage-gated Na⁺ channels 
B) closing of voltage-gated Na⁺ channels 
C) opening of voltage-gated K⁺ channels 
D) closing of voltage gated K⁺ channels 
A) opening of voltage-gated Na⁺ channels 
B) closing of voltage-gated Na⁺ channels 
C) opening of voltage-gated K⁺ channels 
D) closing of voltage gated K⁺ channels

Question 19

Which of the following proteins is NOT part of a four-helix complex that mediates fusion of synaptic vesicles with the plasma membrane?

Accepted Answer

A) NSF 
B) SNAP-25 
C) syntaxin 
D) VAMP 
A) NSF 
B) SNAP-25 
C) syntaxin 
D) VAMP

Question 20

Explain how the expression of the H⁺/acetylcholine antiporter and the choline acetyltransferase enzyme are coordinated.

Accepted Answer

Expression of the H⁺/acetylcholine antip

Exam 21: Nerve Cells

The resting membrane potential in animal cells depends largely on nongated _____ channels.

Fruit flies carrying the shaker mutation have motor neurons with an abnormally long action potential because of:

How do researchers measure ion movements through single channels?

During the development of specialized postsynaptic structures at a neuromuscular junction,preexisting AChR proteins on the surface of the uninnervated muscle are induced to aggregate by:

How are most voltage-gated channels inactivated?

Signaling at synapses is usually terminated by:

Neurotransmitters are stored in:

Reception of taste causes:

Repolarization during the refractory period is largely due to the:

How does opening and closing of voltage-gated cation channels occur?

Evidence that synaptotagmin is the Ca²⁺ sensor for exocytosis of neurotransmitters includes:

Touch receptors are:

Action potentials are propagated in only one direction,down the axon.Explain how the absolute refractory period of the voltage-gated Na⁺ channels and the brief hyperpolarization resulting from K⁺ efflux produces this outcome.

What starts an action potential in a post-synaptic neuron?

How does the nicotinic acetylcholine receptor function as a ligand-gated ion channel at nerve-muscle synapses?

In a human brain,the number of glial cells is:

The birth of new neurons in the adult brain occurs in:

During an action potential,which happens first?

Which of the following proteins is NOT part of a four-helix complex that mediates fusion of synaptic vesicles with the plasma membrane?

Explain how the expression of the H⁺/acetylcholine antiporter and the choline acetyltransferase enzyme are coordinated.

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Vesicular Traffic, Secretion, and Endocytosis

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Cell Organization and Movement II: Microtubules and Intermediate Filaments

Regulating the Eukaryotic Cell Cycle

Integrating Cells Into Tissues

Cell Birth, Lineage, and Death

Immunology

Cancer

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