Nerve gas causes:

Synaptic vesicles contain chemicals called

Arrange the following events in proper sequence during impulse transmission across a chemical synapse:
$(a)$ Fusion of synaptic vesicles with the cell membrane of the presynaptic neuron.
$(b)$ $Ca^{++}$ channels open and $Ca^{++}$ diffuses into the synaptic knob from the extracellular fluid.
$(c)$ Neurotransmitter binds with receptors of the postsynaptic cell.
$(d)$ Release of neurotransmitter by exocytosis.

The movement of the nerve impulse across the synaptic cleft is primarily

How long does the synaptic delay last (in $, ms$)?

Select the incorrect statement regarding synapses :