Biology - Neural Control and Coordination Question with Solution | TestHub
Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): In a chemical synapse, transmission of nerve impulse is unidirectional.
Reason (R): Only the presynaptic membrane releases neurotransmitters.
In light of the above statements, choose thecorrectanswer from the options given below.
Options:
Answer:
Solution:
Assertion (A) is true because the transmission of a nerve impulse across a chemical synapse is always unidirectional, travelling from the presynaptic neuron to the postsynaptic neuron.
Reason (R) is true and correctly explains the assertion. The presynaptic membrane contains synaptic vesicles that release neurotransmitters into the synaptic cleft upon the arrival of an action potential. The postsynaptic membrane contains specific receptors that bind to these neurotransmitters. Since neurotransmitters are released only from the presynaptic side and receptors are located only on the postsynaptic side, the nerve impulse can only travel in one direction.
Therefore, both (A) and (R) are true and (R) is the correct explanation of (A).
Answer: Both (A) and (R) are true and (R) is the correct explanation of (A).
