What
happens once a neurotransmitter is received by a post synaptic neuron receptors

Neurotransmitter binding increases membrane permeability and form a new action potential.

Explanation:

Neurotransmitters are specific lipid-based compounds that are used in the nervous system in chemical signal transduction. They exhibit receptor-specific functions in triggering many regions and physiological responses of the brain and spinal cord or the central nervous system (CNS).

When released into the space between the synapses called the synaptic cleft, they trigger a range of responses. On the postsynaptic cells  they briefly bind to chemical receptors. This results in changes to the membrane which increases the cells' permeability to ions like Na+; a new action potential is created.

c.) polymerase chain reaction

- "unlike the original dna fingerprinting method, dna profiling does not use restriction enzymes to cut the dna. instead it uses the polymerase chain reaction (pcr)? to produce many copies of specific str sequences. pcr is an automated procedure that generates lots of copies of a specific sequence of dna."