The correct answer is: 
"A karyotype can be used for reporting medical concerns and possible genetic disorders
Explanation;
A Karyotype is the number of the chromosome in a cell. In humans, the typical amount of chromosomes is 46. Seldom humans have a varying number of chromosomes and then the karyotype (for example the number) can be used for inscribing for example of genetic disorders- so the answer is that it can be used for reporting of genetic disorders.
 
        
                    
             
        
        
        
All of the chordates have these slits as embryos
 
        
                    
             
        
        
        
The Silurian period occurred before the Neogene period.
I hope this helps.