The nitrogen cycle could no exist without bactria. bacteria that lived inside the ground, catch the nitrogen that has been fixed and covert it into nitrate. 
        
             
        
        
        
Um..... because it could have high levels of mercury, an mercury consumed during pregnancy has been linked to developmental delays and brain damage
        
             
        
        
        
The probability of a crossover occurring between two particular genes on the same chromosome increases as the distance between those
        
             
        
        
        
Answer:
c. by having designated uses for waterways , soil erosion can be completely avoided
 
        
                    
             
        
        
        
Tight junction, Gap junction, Desmosomes