Answer:
the answer will be 
measure the growth of plant that did not recieve fertilizer
perform additional trials
Explanation:
i just took the test and got the answer right
 
        
                    
             
        
        
        
Answer:
Sigma factors bind to the promoter region of a particular gene and facilitating the binding of RNA Polymerase to the promoter region (formation of the RNA polymerase holoenzyme complex) in order initiate transcription of the gene. 
Put simply - Helps RNA Polymerase do it's job. 
 
        
             
        
        
        
Photosynthesis is 
6 CO2 + 6H2O---> C6H12O6 + 6 O2. So unless I understand the question wrong, none is needed to do, but glucose and oxygen are products after the photosynthesis