For many of their illnesses scientist and doctors haven't treated them before so they don't know how to treat them or exactly if the animal can handle the treatment
        
                    
             
        
        
        
The correct answer is peroxisomes.  
Peroxisome refers to a small organelle found in the cytoplasm of various cells that comprises catalase (the reducing enzyme) and generally some oxidases.  
They are the minute vesicles and comprises the digestive enzymes used for dissociating toxic components in the cell. They are not similar to lysosomes on the basis of the kind of enzymes they withheld. The peroxisomes generally contain enzymes that need oxygen, that is, oxidative enzymes.  
 
        
             
        
        
        
The answer is series circuit.