Answer:
By the process of cellular differentiation which consists of physical and functional changes of the cell used by processes at the genetic level. The expression of these in each type of cell is different. That is to say that the type of cell follows at a time of development there is differential activation of some genes and repression of others
 
        
             
        
        
        
Incorporating basic life support, the first thing one should do is survey the scene. Look for any obstacles that will make the response difficult such as shattered glass, fire, etc. Second, call emergency hotline (usually it's 911 but it may differ from other countries). If you are a certified basic life support provider, then continue with the next steps. Next step would be checking the patient's airway, breathing, and circulation (ABC) by checking the if there is blocking the airway, or if the patient can breathe spontaneously, as well as the pulse. Next step would be assess if the patient as a cervical fracture as this should be handled carefully. If the patient is not breathing or has no/decreased pulse then proceed with doing CPR until help arrives. 
        
             
        
        
        
Plates slid past each other