Test Bank - Becker's World of the Cell, 10th Edition
(Hardin, 2022) Chapter 1-26 | All Chapters (Questions
And Answers)(Graded A+)
1) How many neuronal connections are there in the human brain?
A) millions
B) 1 billion
C) 10 billion
D) 100 billion
E) trillions
- ANSWER: e) trillions
2) Each of the following is a type of glial cells except
A) interneurons.
B) oligodendrocytes.
C) astrocytes.
D) Schwann cells.
E) microglia cells.
- ANSWER: A) interneurons.
3) The axon branches of a typical neuron terminate at structures called
A) synapses.
B) boutons.
C) glia.
D) nodes of Ranvier.
E) the myelin sheath.
- ANSWER: boutons
4) The resting potential of a particular nerve cell is −66 mV. Depolarization of the neuron
membrane will shift the membrane potential to
A) −90 mV.
B) −75 mV.
C) 0 mV.
D) +45 mV.
E) +66 mV.
- ANSWER: D) +45 mV.
5) Plasma membrane permeability of which of the following ions is most important in
generating the resting membrane potential?
A) sodium ions
B) potassium ions
C) chloride ions
D) calcium ions
E) None of the above generates resting membrane potential.
- ANSWER: B) potassium ions
,Test Bank - Becker's World of the Cell, 10th Edition
(Hardin, 2022) Chapter 1-26 | All Chapters (Questions
And Answers)(Graded A+)
Using the patch clamp technique, a researcher measures a single channel in a
membrane with a potential of −60 mV. The receptor channel passes 3 pA (picoamperes;
1 pA = 10−12 ampere) of ionic current over a period of 8 msec that it remains open.
6) An electrical current of 1 A is approximately 6 × 1018 electrical charges per second;
how many monovalent ions pass through the channel when it is open?
A) 144,000 ions
B) 18,000 ions
C) 8,640,000 ions
D) 8640 ions
E) Cannot be calculated from the information given.
- ANSWER: A) 144,000 ions
Using the patch clamp technique, a researcher measures a single channel in a
membrane with a potential of −60 mV. The receptor channel passes 3 pA (picoamperes;
1 pA = 10−12 ampere) of ionic current over a period of 8 msec that it remains open.
7) If the resting potential was changed to −66 mV, the next time the channel opened for
8 msec, how many monovalent ions would pass through the channel?
A) 144,000 ions
B) 130,000.
C) 158,000
D) 18,000
E) There is insufficient information to calculate the number of ions.
- ANSWER: A) 144,000 ions
8) At which point in the graph do voltage-gated potassium channels open?
A) A
B) B
C) C
D) D
E) E
- ANSWER: c
9) Based on the graph, the threshold voltage appears to be approximately
A) +60 mV.
B) +30 mV.
C) 0 mV.
D) −30 mV.
, Test Bank - Becker's World of the Cell, 10th Edition
(Hardin, 2022) Chapter 1-26 | All Chapters (Questions
And Answers)(Graded A+)
E) −60 mV
- ANSWER: E) −60 mV.
10) Based on the graph, how soon could another action potential be easily initiated (at
the end of the relative refractory period) after the first stimulus?
A) less than 0.5 msec
B) 1 msec
C) 2 msec
D) 3 msec
E) 4 msec
- ANSWER: D) 3 msec
11) Which point on the graph represents the threshold potential?
A) A
B) B
C) C
D) D
E) E
- ANSWER: b
12) If myelin was lost from the neuron firing the action potential graphed, the action
potential cycle would
A) go much faster than depicted in the graph.
B) go much faster than normal but not peak at 30 mV.
C) go slower than depicted in the graph.
D) go much slower than normal but peak much higher than 30 mV.
E) remain the same. \
- ANSWER: E) remain the same.
13) The parts of the graph indicated between points C and E represent
A) depolarization.
B) hyperpolarization.
C) the absolute refractory period.
D) repolarization.
E) sodium channel activity.
- ANSWER: D) repolarization.
14) If the membrane represented in the graph was stimulated in the presence of a drug
that specifically inhibits sodium channels, the membrane would
A) not depolarize.
B) depolarize for one stimulus but not for a second stimulus.
C) depolarize but not repolarize.
(Hardin, 2022) Chapter 1-26 | All Chapters (Questions
And Answers)(Graded A+)
1) How many neuronal connections are there in the human brain?
A) millions
B) 1 billion
C) 10 billion
D) 100 billion
E) trillions
- ANSWER: e) trillions
2) Each of the following is a type of glial cells except
A) interneurons.
B) oligodendrocytes.
C) astrocytes.
D) Schwann cells.
E) microglia cells.
- ANSWER: A) interneurons.
3) The axon branches of a typical neuron terminate at structures called
A) synapses.
B) boutons.
C) glia.
D) nodes of Ranvier.
E) the myelin sheath.
- ANSWER: boutons
4) The resting potential of a particular nerve cell is −66 mV. Depolarization of the neuron
membrane will shift the membrane potential to
A) −90 mV.
B) −75 mV.
C) 0 mV.
D) +45 mV.
E) +66 mV.
- ANSWER: D) +45 mV.
5) Plasma membrane permeability of which of the following ions is most important in
generating the resting membrane potential?
A) sodium ions
B) potassium ions
C) chloride ions
D) calcium ions
E) None of the above generates resting membrane potential.
- ANSWER: B) potassium ions
,Test Bank - Becker's World of the Cell, 10th Edition
(Hardin, 2022) Chapter 1-26 | All Chapters (Questions
And Answers)(Graded A+)
Using the patch clamp technique, a researcher measures a single channel in a
membrane with a potential of −60 mV. The receptor channel passes 3 pA (picoamperes;
1 pA = 10−12 ampere) of ionic current over a period of 8 msec that it remains open.
6) An electrical current of 1 A is approximately 6 × 1018 electrical charges per second;
how many monovalent ions pass through the channel when it is open?
A) 144,000 ions
B) 18,000 ions
C) 8,640,000 ions
D) 8640 ions
E) Cannot be calculated from the information given.
- ANSWER: A) 144,000 ions
Using the patch clamp technique, a researcher measures a single channel in a
membrane with a potential of −60 mV. The receptor channel passes 3 pA (picoamperes;
1 pA = 10−12 ampere) of ionic current over a period of 8 msec that it remains open.
7) If the resting potential was changed to −66 mV, the next time the channel opened for
8 msec, how many monovalent ions would pass through the channel?
A) 144,000 ions
B) 130,000.
C) 158,000
D) 18,000
E) There is insufficient information to calculate the number of ions.
- ANSWER: A) 144,000 ions
8) At which point in the graph do voltage-gated potassium channels open?
A) A
B) B
C) C
D) D
E) E
- ANSWER: c
9) Based on the graph, the threshold voltage appears to be approximately
A) +60 mV.
B) +30 mV.
C) 0 mV.
D) −30 mV.
, Test Bank - Becker's World of the Cell, 10th Edition
(Hardin, 2022) Chapter 1-26 | All Chapters (Questions
And Answers)(Graded A+)
E) −60 mV
- ANSWER: E) −60 mV.
10) Based on the graph, how soon could another action potential be easily initiated (at
the end of the relative refractory period) after the first stimulus?
A) less than 0.5 msec
B) 1 msec
C) 2 msec
D) 3 msec
E) 4 msec
- ANSWER: D) 3 msec
11) Which point on the graph represents the threshold potential?
A) A
B) B
C) C
D) D
E) E
- ANSWER: b
12) If myelin was lost from the neuron firing the action potential graphed, the action
potential cycle would
A) go much faster than depicted in the graph.
B) go much faster than normal but not peak at 30 mV.
C) go slower than depicted in the graph.
D) go much slower than normal but peak much higher than 30 mV.
E) remain the same. \
- ANSWER: E) remain the same.
13) The parts of the graph indicated between points C and E represent
A) depolarization.
B) hyperpolarization.
C) the absolute refractory period.
D) repolarization.
E) sodium channel activity.
- ANSWER: D) repolarization.
14) If the membrane represented in the graph was stimulated in the presence of a drug
that specifically inhibits sodium channels, the membrane would
A) not depolarize.
B) depolarize for one stimulus but not for a second stimulus.
C) depolarize but not repolarize.
