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>
        
                    
             
        
        
        
A population decrease in primary producers would affect the ecosystem negatively because everyone who ate the primary consumers would have a lack of food.
        
             
        
        
        
Answer:
wolf families are wolf packs l. they are usually led made up of a male parent and a female parents along with their pups
 
        
                    
             
        
        
        
Answer:
c) adrenocorticotropic hormone (ACTH).
Explanation:
A tropic hormone is defined as the hormone which is secreted from one gland and acts on another gland. ACTH is released by anterior portion of our pituitary gland during the condition of biological stress. After it is released, it acts on adrenal gland so that adrenal gland could secrete another hormone named as cortisol (steroid hormone). In response to stress, cortisol increases blood sugar level, elevates brain's use of glucose etc. so as to counter stressful situation. 
Apart from this cortisol also helps in regulating our metabolism, reduces inflammation and controls salt and water balance.