Answer:
The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past. 
 
        
             
        
        
        
The enzyme pepsin functions with a very low pH of around 2. It is found in the stomach, with the acidity coming from the hydrochloric acid present there. it breaks proteins into amino acids.
        
             
        
        
        
Answer:
Grey and White Matter.
Explanation:
When looking at an image of trasnverse section of the spinal cord the grey matter is almost butterfly shapped and it has the central canal in the middle. The white matter is surrounding the butterfly shaped, grey matter. 
 
        
                    
             
        
        
        
Answer:
Behavior genetics.
Explanation:
Genetics may be defined as a branch of biology that studies the inheritance and variation of the inherited characters. Mendel is known as the father of the genetics.
Behavior genetics may be defined as the field of the scientific research that uses the genetic methods to investigate the behavioral differences in the individual. This genetics uses the limits of genetics and environmental impact on the individual's behavior.
Thus, the answer is behavior genetics. 
 
        
             
        
        
        
Oxygen evaporates from the water