It is true that enzymes in the digestive tract catalyze hydrolysis reactions.  The reaction happens when a molecule of water is added to the amino acids that are already in the digestive tract. 
        
             
        
        
        
It would be d because a cell is least complex and organ system is most complex
        
             
        
        
        
No it isnt a rational nu7mber.
        
                    
             
        
        
        
Mostawa is the correct answer
        
             
        
        
        
 DNA, Chromosomes, Nucleus, Cell, Organism
Explanation:
DNA makes up the Chromosomes, which are stored in the nucleus, which is the brain of the cell, and cells make up organisms.