A covalent bond is a chemical bond which involves the sharing of atoms.
        
                    
             
        
        
        
It's <span> called an autotroph or</span><span> heterotroph</span>
        
             
        
        
        
water molecule is one of few molecule that lack carbon atom 
h2o
 
        
                    
             
        
        
        
To identify the host cell that has taken up the gene of interest