1. molecul of DNA 2. dna packed (coild) around histon h1 3.second stage of dna packing -solenoid thread 4. third stage of packing-chromosomal thread 5.chromosome-chromosomal threads are packed inside
        
             
        
        
        
 The pericardium <span>is a double-walled sac containing the heart. The </span>pericardial<span> sac has two layers, a serous layer and a fibrous layer.</span>