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.
