Our nervous system runs on chemical synapses ! that means we need chemical to transfer information from one neuron to another !
so when the signal reaches the synaptic knob of one neuron , it stimulates the neurotransmitters containing vacuoles to release the neurotransmitters !
the neurotransmitters may be dopamine, acetylcholine etc and after reaching the dendrites of other neuron, it stimulates signal in the other neuron and thus a signal travel from one part of body to other !
After collecting specimens from many areas of the world, Darwin noted the similarities in them. He discovered that new kinds of species could gradually grow into new ones over years.
I hope this helps ;)
Some producers are Water Ivy, some "river grass" and many more organisms.