Bacteria are unicellular microorganisms that can be found everywhere in the environment. Viruses are microorganisms that can only reproduce within the cells of a host organism. 
The differences between viruses and bacteria include;  
- Viruses do not have any cell and are considered between living and non-living things, while bacteria have one cell (Unicellular) and are living organisms.
- Viruses are smaller in size (20-400 nm) when compared with bacteria (1000 nm).
- Viruses do not have a cell wall but a protein coat is present, while bacteria have a cell wall that is composed of peptidoglycan.
- Viruses require a living cell to reproduce, while bacteria can reproduce by itself.
- The DNA or RNA of viruses is enclosed inside a coat of protein, while that of bacteria floats freely in the cytoplasm within the cell.
 
        
                    
             
        
        
        
Answer:
A. mitochondria is the powerhouse of the cell
 
        
                    
             
        
        
        
The Silurian period occurred before the Neogene period.
I hope this helps.
        
                    
             
        
        
        
I think the top three statements are the answer.