<span>epidemiological studies</span>
        
             
        
        
        
Answer:
2. Can carry less oxygen and more carbon dioxide.
Explanation:
Sickle cell anemia damages and inhibits hemoglobin in red blood cells reducing how much oxygen they can carry.
 
        
             
        
        
        
Answer:
D
Explanation:
An infection is when something invades your body, therefore, you are infected with micro-organisms making it D.