Answer:
Insulin causes the body's cells to take in and store glucose, lowering the blood glucose concentration. If blood glucose gets too low, the body releases glucagon, which causes the release of glucose from some of the body's cells.
Explanation:
 
        
             
        
        
        
Indigestable food moves from the small intestine to the large intestine where water is absorbed back into the body. The waste is then passed through the rectum and excreted from the anus. 
I would say the large intestine.
        
             
        
        
        
The right answer is D (less responsive to antigens)
It is proven that, after puberty, thymus activity (an organ that is included in the lymphatic system, producing T cells that pick up antigens) decreases and that in adult and aged people the thymus has no role. Work done in humans indicate that in fact the cellularity begins to decline from birth in favor of lymphocyte perivascular spaces and connective and adipose tissue, which leads to a decrease in the capture of antigens.
 
        
             
        
        
        
Answer:
D. New species of iguanas
Explanation:
A- doesn't make sense because nature changes every day.
B- More islands is possible but not likely considering your other options.
C- More tortoises is also possible but because I haven't read your text book or where your learned this information I can't be sure this is it. 
D- Is the likeliest 
 
        
                    
             
        
        
        
Incorrect and false
Humans have innate behaviors and these are exhibited as instinctive behaviors that acts as an impulse, drive or impetus without a rational guidance. These are survival behaviors that aid to the individual's own growth in the harsh environment.