The reduced potential causes hundreds of <u>voltage-gated sodium</u> channels  to open on that part of the cell membrane. The depolarization of the cell causes more of <u>voltage-gated sodium </u>channels to open in adjacent parts of the cell membrane. This begins the wave of of <u>depolarization</u>  moving down the axon. Depolarization begins at the <u>axon hillock.</u>
Explanation:
When there is no neuron signaling it becomes polarized, termed as resting membrane potential (RMP) at a threshold voltage (around -55 mV), due to the action of the sodium-potassium pump and the potassium leak channels.  
When a change in the RMP occurs, depolarization takes place which causes the voltage-gated sodium channels to open and sodium ions rush into the nerve cell which in turn will increase the voltage threshold to nearly around +40 mV and also charges the neuron positive. This depolarization moves down the axon. This increase in threshold stops the sodium influx and opens the potassium channels to rush the potassium out of the cell. 
All these actions decrease the membrane potential leading to a wave of depolarization and going back to resting state. Depolarization begins depending upon the potential gradient at the axon hillock.
 
        
             
        
        
        
Answer:
The scientist is studying oxygen which can also be found in protien. oxygen is the element which makes up to 65% of human body mass. It is also found in proteins inside the body.   
 
        
             
        
        
        
Answer:
Allele frequencies in the population is 0.6
Explanation:
The first step in testing whether a population is in Hardy-Weinberg equilibrium is the frequency of an allele in a gene pool is the number of copies of that allele divided by the total number of copies of all alleles at that locus.
 
        
             
        
        
        
Air rises when it is warmer
        
             
        
        
        
Answer:
Look at the explanation!
Explanation:
The Mercator map projection is a cylindrical map projection that was presented by Gerardus Mercator in 1569. Gerardus  Mercator was a Flemish geographer and cartographer. It became the standard map projection for navigation because of it's cool one of a kind property of "representing any course of constant bearing as a straight segment."