The answer is; Pepsin
Pepsin is first secreted by the chief cells of the stomach wall and the inactive precursor called pepsinogen. When pepsinogen interacts with the acidic environment of the stomach due to hydrochloric acid, it is turned to pepsin. The pepsin breaks down large protein molecules to smaller molecules. 
 
        
             
        
        
        
Answer: False
Explanation:
Food irradiation is a process in which the food is exposed to the treatment of radiations. This helps in increasing shelf life and decreasing the colonization of the pathogens on the food. This process does not make the food radioactive. 
 
        
             
        
        
        
Answer: The role of substance A in photosynthesis is: it combines with water to form glucose.
Explanation:
 
        
             
        
        
        
The answer would be d) phenotype. The phenotype is the physical characteristic while the genotype is the combination of alleles from the parent--basically the part that you can't really see. The color of a flower is prominent, so that would be its phenotype. An organism's phenotype can also include certain behavioral characteristics as well, not just the way it looks! Hope this helped :)
        
             
        
        
        
Answer:
C. When the ice melts, it will model infiltration as it absorbs into the soil.
I got it right on USATESTPREP.