Question

A list of events occurring in the transmission of nerve impulse across the synapse is given below in a random order.
(i) Opening of specific ion channels allows the entry of ions, a new action potential is generated in the post-synaptic neuron.
(ii) Neurotransmitter binds to the receptor on post synaptic membrane.
(iii) Synaptic vesicle fuses with pre-synaptic membrane, neurotransmitter release into synaptic cleft.
(iv) Depolarisation of pre-synaptic membrane.
(v) Arrival of action potential at axon terminal.
Which of the following options represents these events in a correct order?

• A. $\left(v\right)\to \left(iv\right)\to \left(iii\right)\to \left(ii\right)\to \left(i\right)$
• B. $\left(i\right)\to \left(ii\right)\to \left(iii\right)\to \left(iv\right)\to \left(v\right)$
• C. $\left(i\right)\to \left(ii\right)\to \left(iv\right)\to \left(iii\right)\to \left(v\right)$
• D. $\left(v\right)\to \left(iv\right)\to \left(iii\right)\to \left(i\right)\to \left(ii\right)$

Answer 1

The correct option is A $\left(v\right)\to \left(iv\right)\to \left(iii\right)\to \left(ii\right)\to \left(i\right)$

Arrival of action potential- depolarisation- synaptic vesicles release neurotransmitters- they fuse with dendrites of next neuron- neurotransmitter binds to receptor- voltage gated sodium ion channels open up- sodium ion influx- a new action potential is generated- cycle repeats.

So, the correct option is A.