<span>Alleles are usually represented by three different methods using two alphabets; when the two alphabets are small letters, it means that both alleles are recessive; when the two alphabets are capital letters, it means that both alleles are dominant and when one of the letter is capitalized and the other a lower case, it means that one of the allele is dominant while the other is recessive. Genotype CC means that the two alleles for curly hair are dominant.</span><span />
In a dominant cross, the chance of the dominant phenotype showing up in one of the offspring is 3/4, since the dominant genes are being shown here.
Cuz of the refraction of light
When the mutation is more beneficial compared to the current alleles