DNA synthesis occurs during the S phase, between the G1 and G2 phases of interphase. DNA replication is therefore complete before the mitotic phase begins.
        
             
        
        
        
The nucleus houses the genetic info of a cell. :)
        
                    
             
        
        
        
Answer:
Bubbles are nothing but the oxygen which arise around the green parts of the plant. 
 
        
             
        
        
        
Organ system is the answer according to me if it is one word question