Protein. im absolutely certain
        
                    
             
        
        
        
Answer:
The simplest virions consist of two basic components: nucleic acid (single- or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.
 
        
                    
             
        
        
        
Answer:
cellular resperation; ATP;energy;digestive system;circulartory ;energy; glucose; water; carbon dioxyide ; mitocondria 
Explanation:
  
 
        
             
        
        
        
Crossing over occurs but on in meiosis 1