Answer:
Correct answer is c. It is the final electron acceptor in the aerobic respiration.
Explanation:
Oxygen is a substrate of the aerobic respiration, but it is not the only one. Glucose is also a substrate. 
Oxygen is used in the cells to be the final electron acceptor, this means that receives the electrons from NADH and FADH2. That is why, when there is no oxygen available for aerobic respiration, the NADH and FADH2 cannot be oxidized and therefore remain in their reduced form. As a consequence, they cannot be re-utilized during different cellular processes that are NAD+ and FAD dependant, such as glycolysis, pyruvate oxidation and cellular respiration. This means that the ATP synthesis stops. 
Oxygen itself does not transport any electrones, this are transported by the cytochrome complex in the mitochondrial membrane. But oxygen is key in receiving those electrones, therefore a very important piece of the electron transport across the mitochondria.
 
        
             
        
        
        
Answer:
Personal protective equipment may include items such as gloves, safety glasses and shoes, earplugs or muffs, hard hats, respirators, or coveralls, vests and full body suits.
 
        
             
        
        
        
Answer:
Dr. Mullis is most likely a psychologist testing for dyscalculia or another math learning disability rather than simply needing extra support in math. A psychologist can also give input as to the possibility of other learning differences, such as ADHD or dyslexia.
 
        
             
        
        
        
Pathogens that cause communicable diseases:
Viruses.
Bacteria.
 
Fungi. 
Protists.
Diseases that are caused by bacteria:
Cholera.
Leprosy.
Tuberculosis.
Plague.
Syphilis.
Anthrax.
 
        
                    
             
        
        
        
Answer:
The answer is D: decreased risk of cancer.
Explanation:
As the men get older, the risk of presenting a neoplasm increases; The highest incidence of prostate cancer has been scientifically demonstrated in men over 50 years of age, such as breast cancer, and a higher frequency of lung and gastric cancer has also been seen.