Answer:
I think the answer would be 'bonding to each other 
 
        
                    
             
        
        
        
Actually, all four of them are correct. Bacteria are responsible for all of them and they are very important.
        
                    
             
        
        
        
Fungi are heterotrophic. They get their nutrition by absorbing organic compounds from the environment. Fungi, along with bacteria that are found in soil, are the primary decomposers of organic matter in terrestrial ecosystems.
        
             
        
        
        
Answer:
I'm pretty sure it is a heterotroph