Here it is hoped it helped
 
        
             
        
        
        
1) As blood groups A and B are equally dominant so the individual will express both characteristics in the phenotype. 
Notice how in all the 3 other examples the organism is only expensive 1 version (allele) of each gene. For example the mouse with brown fur may have 2 brown fur alleles (and so would have to express this characteristic even if it was recessive) but it could have 1 allele which is less dominant than the brown, in which case brown would be expressed. In this case the alleles were not co-dominant.
        
             
        
        
        
Caa and cgu is the codons
        
             
        
        
        
Answer:
Mutation plays an important role in evolution. The ultimate source of all genetic variation is mutation. Mutation is important as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele.