本题目来源于试卷: Interaction & Interdependence C.5 Neural Signaling，类别为 IB生物学
[单选题]
What happens if the threshold pote)xfbcto m x/kn1 ew(y ,v1v5vpr+k/*qntial is not re310su 2vmcgwq k qxx d e:rq;tw.3;ie5ached ?
A. No action potential is triggered.
B. A lower amplitude action potential is triggered.
C. Neurotransmitters are released at the synaptic cleft.
D. The action potential moves backwards to the dendrites.
参考答案: A
本题详细解析:
Explanation: The all-or-none law states that an action potential will only be transmitted if a threshold potential is reached, and the size of the action potential does not vary. Choice A is correct. Choice B is incorrect as if the threshold potential isn’t reached, then no action potential is triggered. Choice C is incorrect because if the threshold potential is not reached, then an action potential is not triggered and so neurotransmitters are not released at the synaptic cleft. Choice D is incorrect as an action potential only moves in one direction.
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