Structurally, DNA and RNA are nearly identical. As mentioned earlier, however, there are three fundamental differences that account for the very different functions of the two molecules. RNA has a ribose sugar instead of a deoxyribose sugar like DNA. RNA nucleotides have a uracil base instead of thymine.
        
             
        
        
        
Answer:  "symbiosis" ;  or,  a "symbiotic relationship" .
_____________________________________________________________
        
             
        
        
        
<span>Humans shouldn't use nonrenewable sources otherwise the resources will disappear. Renewable Sources: Sun, wind, maybe water.</span>
        
             
        
        
        
Chromosems is the right answer