Because they are only expressed in 1 in 4 phenotypes, but are carried in 3 in 4 genotypes
Sickle cell anemia is a disease that is controlled by alleles S and s .three possible combinations are SS , Ss ans ss . The most important reason why this allele is present in whole world including...
An allele is a variation or a type of gene
searching of gene..... or theallele of a gene which has some significant effect
ALLELE:MEANS VARITIMS OF THE SAME GENEL..