Answer:
 q = 0.42
Explanation:
This question is an example of Hardy-Weinberg question and there are two equations necessary to carry out this question;
p + q = 1
p² + 2pq + q²  = 1
where;
p =  the frequency of the dominant allele
q =  the frequency of the recessive allele
p² = the frequency of individuals with homozygous dominant genotype
2pq  = the frequency of individuals with heterozygous genotype
 q² = frequency of individuals with the homozygous recessive genotype
Since the total  population = 425
 q² = 
= 
 q² = 0.1765             
 To find q; we need to square root both side to           eliminate the square from  q².
∴  
 
 q = 0.4201 
 q = 0.42       (to two decimal places) 
 
        
             
        
        
        
While both will equate changes in a genetic chain, deletion would have more severe consequences.  A substitution mutation usually only causes minor disorders and diseases, like sickle cell anemia.  Whereas deletion causes much more serious diseases, like cystic fibrosis, and turner syndrome which is  where a female is born with only one X chromosome.  
 
        
             
        
        
        
A dependent variable is something that relies on another variable; it is what is being measured in an experiment.