Can you please take a picture of the question? I don't understand what you're talking about
        
                    
             
        
        
        
It occurs at the metaphase of the cell division cycle. 
 
        
             
        
        
        
Answer:
They use a hard shell, but not hard enough though because we humans can get through them hehehe
 
        
             
        
        
        
I believe the correct answer is homeostasis. 
        
                    
             
        
        
        
Las rocas están hechas de minerales!!