On May 14, 1796, Jenner<span> took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On July 1, </span>Jenner<span> inoculated the boy again, this time with smallpox matter, and no disease developed. The </span>vaccine<span> was a success.</span>
        
                    
             
        
        
        
They are prokyartic cells 
        
                    
             
        
        
        
Answer:
Permeability of plasma membrane is the rate of passive diffusion molecules across the biomembrane.