It sends an impulse back to the cell body of a neuron
 
        
             
        
        
        
You kinda need to put something there? We don’t know what the choices are so there’s really no way we’d know what choice is an example of federalism
        
             
        
        
        
Broccoli is found in it
hope it helps
        
             
        
        
        
The answer for the above question is Mutation. 
Mutations are random spontaneous changes that occur suddenly in the DNA. A single mutation can have a large effect, however in may cases evolutionary changes are based on the accumulation of many mutations. The gene flow is any movement of genes from one generation to another and is an important source of mutation 
        
             
        
        
        
Answer:
speed up the rate of virtually all of the chemical reactions that take place within cells.