It is muscle and nerve tissue
        
             
        
        
        
If it is a healthy environment then the atmosphere will be happy meaning no dirty streets etc
        
             
        
        
        
Answer:
A) To make sure that the effect is not occuring through actions in the nervous system
Explanation:
In the above scenario, researchers actually studies the effect of hormone to the organ but they are in a situation to study the effect on organ are either hormone base or nervous system base (neurons). For this reason they will cut the neurons to study the effect of hormone on the organ. 
So, to check the effect of hormone they should cut the neurons to make sure these effect are not due to actions of nervous system. 
 
        
                    
             
        
        
        
MUTATIONS  lead to duplications actually increase the number of genes in a genome.
        
             
        
        
        
A tolerance range is an environment where something can survive in. But if their is to much of one factor or to little this can effect the tolerance range.