I think the answer is the Endoplasmic Reticulum
        
             
        
        
        
Gene flow does not promote speciation, whereas season of fertility, natural selection, and genetic drift do. 
        
                    
             
        
        
        
A) moves  substances across the cell membrane
        
             
        
        
        
What is the primary cellular site for the production of polypeptide chains? Ribosomes
        
             
        
        
        
If a test tube has been used, and its contents is supposed to be disposed, carefully pour the contents to the lavatory with a confirmation of a professional (as it may damage the pipelines of the sink) and ensure that there are no splashes created that can contact the human skin. Wash the test tube thoroughly and let dry.