The system of classification relates to the diversity of species because the system of classification is how we organize the diversity of species. With out it we would have a hard time trying to determine which animals belong with which group. There would be no order, just chaos of trying to determine animal likeness of one another. 
To cut this answer short, it helps them organize organisms. 
        
             
        
        
        
Construction contributes to soil erosion because;
C. It removes vegetation from the building site.
 
        
                    
             
        
        
        
Answer:
Retinoblastoma is more common in people due to the mutation of RB gene in them.
Explanation:
Retinoblastoma is a disease that affects the eyes of an individual. It is more commonly eye cancer which occurs on the retina of the eye. Retinoblastoma mainly affects younger children. 
When the RB gene is mutated or it is deleted already on any one of a homologous chromosomes, then only one hit rather that two which is needed to cause the development of retinoblastoma and hence the probability is of retinoblastoma to occur is higher in the individuals who have already inherited the RB deletion and also have a genetic predisposition for the retinoblastoma.
 
        
             
        
        
        
This sums up most of them