That's correct - it's a square where on one axis, the paternal allele (allele = one of the possible forms of the same gene), and on another the maternal allele is listed. Often, it's also indicated whether an allele is recessive or dominant.
Then, in the table that results, all the possible "combinations" of allele between the paternal and maternal party are created. If you count how often a certain combination appears, it indicates the likelihood of that combination.
See the picture (though it is directly from Wikipedia, please note). The likelihood of BB is 25%, of Bb is 50%, and of bb 25%.
 
        
        
        
P:               DdCc          x           DdCc
g:      DC  Dc  dC  dc           DC  Dc  dC  dc
1.)
 
              DC                       Dc                   dC                     dc
DC       DDCC                   DDCc              DdCC              DdCc
Dc        DDCc                    DDcc              DdCc               Ddcc
dC        DdCC                   DdCc               ddCC              ddCc
dc         DdCc                    Ddcc               ddCc               ddcc 
2.)
G= 1:2:2:1:1:4:2:2:1
3.)
F= 9:3:3:1
        
             
        
        
        
<span> Answer: 1/4 will by AB, type AB blood; 1/4 will be AO, or type A Blood; 1/4 will be BO, or type B blood; 1/4 will be OO, type O Blood</span>
        
             
        
        
        
Lava is at the center of the earth witth lava 
        
                    
             
        
        
        
Answer:
D.-
Explanation:
A control group is needed to carry out the experiment, that control group is the one that is not injected with anything.  Ethanol and pesticide need to be injected into separated groups to document whether it is one or the other that is harmful