<span>I think the answer is A test cross can be used to: study how traits are inherited. </span>
        
             
        
        
        
One way that cancer can form is when abnormal cells have uncontrolled growth, old cells die and get added on to which I believe creates tumors. 
 
        
                    
             
        
        
        
The name comes from a latin word meaning to glue or bind together. DNA ligase catalyses the joining of DNA fragments (usually those produced by restriction enzymes). Thus different genes can be put into vectors and moved into other hosts.