Answer:
well you didnt give me a link to the story or text so i dont have any info to answer sry ;(
Explanation:
 
        
                    
             
        
        
        
Answer:
I think option (C) is right answer
 
        
                    
             
        
        
        
D. He controlled variables by studying one or two traits at a time
        
             
        
        
        
The cardiovascular system I think. Hope this helps
        
                    
             
        
        
        
For humans, we have 19,000 protein-coding genomes. For every gene, there are 2 alleles. This means that humans have 38,000 alleles (19,000×2=38,000).