The boundary separates them<span />
        
                    
             
        
        
        
False in order for an ecosystem to survive there has to be some sort of competition. for example, if there were no sharks to eat little fish the little fish would over populate and then the little fish would run out of food which then means that whatever the little fish ate is now extinct and so on hinting the food chain's name. If it wasn't for competition nothing would survive
        
             
        
        
        
Answer:
b. They express the appropriate receptor.
Explanation:
The signal transductions are extraordinarily specific and sensitive. Specificity is achieved by a <u>precise molecular complementarity between the signal molecules and the recepto</u>r. For example, the thyrotropin-releasing hormone produces a response in cells of the adenohypophysis, but not in hepatocytes, which lack the receptors to this hormone.
 
        
             
        
        
        
Answer:
Forestation.
Explanation:
When life is created on land where there originally was no life, wind brings over pioneer species, such as grasses. Over time, life takes advantage and grows bushes, trees, and so on.