Gel electrophoresis is a method of genetic analysis which involves seperating segments of DNA based on their size and charge.
It involves cutting DNA with various enzymes, then placing the DNA in an agarose gel. An electrical current is then run through the gel. Because DNA is a polar molecule the DNA segments will travel through the agarose cell as the current is applied. Larger fragments will travel shorter distances than shorter fragments. Two plates with 2 different DNA samples will be conducted and the orientation of the DNA strands will be used to make an analysis by comparing the 2 plates. 
 
        
             
        
        
        
Not to be concerned as long as the diet as a whole provides average amounts 
        
             
        
        
        
The genotype would be X'Y for the father (he would be colorblind)
The genotype would be X'X for the mother (she would be a carrier)
The offspring would be X'X' _ X'X_ X'Y_ XY
The ratio would be 1:1 normal to colorblind
Hope this was helpful(;
        
             
        
        
        
Three reasons a species could become extinct include, deforestation, being overhunted, not enough food available.