The correct terms to fill in the blanks are gastric cavity and extracellular. In cnidarians, the mouth of both the medusa and polyp form opens into an internal gastric cavity where extracellular digestion takes place. The polyp and medusa are body forms that can be found in the phylum Cnidaria. The polyp is a nonmotile body form while the medusa is a free swimming body form.
        
             
        
        
        
Answer:
At the very bottom
Explanation:
When examining a cross section of rock layers, the oldest layer is on the bottom. This is because over time, newer rock layers continued to form on top of the oldest one.
 
        
             
        
        
        
They cannot hibernate in winter
        
             
        
        
        
Answer:
<em>Cell Differentiation</em> is the process through which cells become specialized. 
Think about the name, cells become different from one another, becoming specialized into different types. 
 
        
                    
             
        
        
        
Organisms on earth live in the Biosphere