I believe the answer is: Different scientists use different data for investigation.
I say that because different scientists have different equipment, ideas, and have different methods. I hope I was right and i hope it helped and i wasn't to late to answer this question.
        
                    
             
        
        
        
Bacteria can obtain energy and nutrients by performing photosynthesis, decomposing dead organisms and wastes, or breaking down chemical compounds.
Bacteria can obtain energy and nutrients by establishing close relationships with other organisms, including mutualistic and parasitic relationships.
        
                    
             
        
        
        
Meiosis where gametes are made in order for sexual reproduction.