Answer: feed-back 
When the product of a metabolic pathway accumulates, it may be able to slow down or turn off the pathway by inhibiting the activity of an enzyme that catalyzes an early step in the pathway. This is referred to as feed-back inhibition.
Explanation:
Feed-back inhibition is said to occur when the final product of a biochemical pathway signal the inactivation of the starting materials of the pathway. 
For example: when pyruvate signal the inactivation of phosphofructokinase, the glycolytic pathway gets turned off. 
 
        
             
        
        
        
A. The hemisphere of the Earth is tilted more toward the Sun.
        
                    
             
        
        
        
Explanation:
The two main types of exocrine secretory cells of the stomach are parietal cells and chief cells. Parietal cells secrete hydrochloric acid and chief cells secrete digestive enzymes such as pepsin
 
        
             
        
        
        
Answer:a 
a possible explanation for this occurrence is that a test tube or dropper was accidentally used repeatedly without being sterilized, causing sample cross-contamination. DNA in this test case did not confirm that the father of the second child was another client of the fertility clinic who had never met the mother...therefore this is a possibility. 
Explanation:
 
        
             
        
        
        
Answer: D. They are not well adapted to the Australian climate.
Explanation:
Just took the exam