If you flip a penny, the chance of it turning up heads is
1/4
1/2
3/4
0/4

1/2 because it would land either heads or tails. 2 possibilities of each landing makes it 1/2.

Neurotransmitters are messengers responsible for communication between neurons. they are released from synaptic vesicles and are received by receptors.  the communication is referred to as neurotransmission. the following statement is true about neurotransmitters: a. they're stored in synaptic vesicles in the axon.