During synaptic transmission:a. receptors that bind neurotransmitters trigger a change in postsynaptic membrane potential. b. neurotransmitter-filled vesicles fuse with the postsynaptic membrane. c. neurotransmitters are absorbed by the postsynaptic membrane. d. voltage-gated calcium channels open in the postsynaptic membrane.

a. receptors that bind neurotransmitters trigger a change in postsynaptic membrane potential.

Explanation: Synaptic transmission is the communication between a neuron with another neuron. When the electrical impulse reaches the synaptic vesicles, they release their contents of neurotransmitters.

The neurotransmitters released into the synaptic cleft binds with the postsynaptic receptors and activates a receptor in the postsynaptic membrane. The binding of neurotransmitter results to the opening of channels in the neuron. Also, binding of neurotransmitters may influence the postsynaptic neuron in either an inhibitory or excitory way.

The binding of neurotransmitters to receptors in the postsynaptic neuron can trigger either short term changes or long-term changes.

A change in postsynaptic membrane potential.By causing opening of ligand gated  Sodium-channels (on the membrane of postsynaptic neuron) which cause sodium influx, reversal of charges, and therefore depolarization.

If the  stimulus is strong enough more sodium channels opens,and therefore action potential is generated. if the potential is sustained to the threshold levels  action potential is propagated along the postsynaptic nerve fibre as inhibitory or excitatory  postsynaptic potential.( IPSP / EPSP,).

Thus changing the potential  from the Pre- synaptic potential that crosses the synaptic cleft to Postsynaptic potential in the membrane of  postsynaptic nerve fiber.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.

answer: all : )

explanation: