Answer:
The presence of an additional chromosome
Explanation:
Look at "pair" 21. See how there are THREE chromosomes instead of TWO? Normally, there would only be two chromosomes in each pair but this karyotype shows a trisomy (see def. below) of the 21st pair. This was caused by a nondisjunction mutation of the 21st pair. The is also the karyotype of a person with Down's Syndrome.
Definition of Trisomy:
A condition of the presence of three chromosomes in a pair instead of two. This normally causes developmental irregularity.
 
        
             
        
        
        
It is Protozoa because it is not logical for it be any of the other. Hope this helped.
        
             
        
        
        
Solid has the least energy, liquid has a the middle amount of energy and gas has the highest amount of energy