Physician recommends radiation therapy because radiation therapy helps in preventing cellular growth. It uses high-energy radiation to shrink tumor or kill cancer cells. It may be used to cure or to control malignancy when the tumor can no longer be removed or when lymph node involvement is present; also, it can be used prophylactically to prevent spread. Radiation therapy kills cancer cells by damaging their DNA which is the molecules inside cells that carry genetic information and pass it from generation to generation. Radiation therapy can either damage DNA directly or create charged particles within the cells that can in turn damage the DNA. Cancer cells whose DNA is damaged beyond repair stop dividing or die and when these cells die, they are eliminated by the body through natural process.
        
             
        
        
        
Answer:
Phospholipids serve as a major structural component of most biological membranes, e.g. cell membrane. The phospholipids are vital to the function of the cell membrane. Being amphipathic, their presence creates an effective barrier preventing the entry of all 
 
        
                    
             
        
        
        
Answer:
A mutation can occur when mistakes are made during DNA replication.
Explanation:
 
        
             
        
        
        
<span>This indicates that energy consumption could have fluctuated. </span>
        
             
        
        
        
Primary producers have the largest amount in a trophic pyramid. therefore this statement is false