B. sexual selection, which alters allele frequencies in the gene pool.
        
                    
             
        
        
        
Answer:
During El Nino and LA Nina, opposing weather conditions are observed
Explanation:
Both El Niño and La Niña are weather patterns that occurs in the Pacific Ocean. It causes changes in global temperature and rainfall levels. 
 
        
                    
             
        
        
        
Answer: radiation i think 
 
        
             
        
        
        
They don't need to be near water for reproductive purposes!
        
             
        
        
        
A on the second one . anti biotics can help with the body system.