What is the approximate threshold value for mammalian neurons?
-55 mV
-80 mV
+35 mV
0 mV
Correct Answer : A
The approximate threshold value for mammalian neurons is -55 mV.
The threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential.
Most often, the threshold potential is a membrane potential value between –50 and –55 mV
The membrane potential of a neuron is determined by the distribution of ions across the cell membrane.
At rest, the inside of a neuron is more negative than the outside due to the presence of negatively charged proteins and other molecules.
The movement of ions across the cell membrane can change the membrane potential.
For example, when sodium ions enter the cell, they make the inside of the cell more positive (less negative), causing depolarization.
Choice B is incorrect because -80 mV is below the typical threshold value for mammalian neurons.
Choice C is incorrect because +35 mV is above the typical threshold value for mammalian neurons.
Choice D is incorrect because 0 mV is above the typical threshold value for mammalian neurons.
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Explanation
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Choice D is incorrect because active transport using energy is not involved in the movement of carbon dioxide from the blood into the alveoli.
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Explanation
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Explanation
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Explanation
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Explanation
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Choice A.
3’ AGCTAGCGT 5’ is not correct because it is not complementary to the given strand.
Choice C.
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Choice D.
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Explanation
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Explanation
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Explanation
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Choice B.
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Choice C.
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Choice D.
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Explanation
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Choice B.
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Choice C.
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Choice D.
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