Answer:
The answer is: Clonal selection produces memory cells that are long-lived and can recognize the antigen in the future.
Explanation:
 
        
             
        
        
        
Generally, epithelial cells serve the function of protection of the inner layers of the structure they are on. The fact that these columbar epithelium and transitional epithelium cells have smooth walls and are dome shaped allows them to stretch. This stretching helps the bladder retain more urine than it would be able to if the epithelial cells were rigid.
        
             
        
        
        
Answer: it could mean you are nervous people often refer butterflies to a nervous jittery feeling in their stomach or it could mean your pretty or when people call other people names and things like that then you could say im just a catterpillar now but im gonna transform into a beautiful butterfly soon id.k im not really sure