28. bacteria and fungi.
29. answer 3
30. answer 2
        
                    
             
        
        
        
Answer is Biogeochemical cycles.
In an ecosystem biotic (living) abiotic (non-living) components constantly interact each other. During these interactions, there is a transfer of nutrients between living organisms and the non-living environment. Thus, there is recycling of inorganic matter between living organisms and their non-living environment. This cycling of matter is called biogeochemical cycles.
  
 
 
        
             
        
        
        
I think it’s the first one
        
                    
             
        
        
        
Answer: Mitochondria are shaped to maximize their productivity. They are made of two membranes. The outer membrane covers the organelle and contains it like a skin. The inner membrane folds over many times and creates layered structures called cristae.