What evidence supports the claim that the H allele is dominant and the h allele is recessive?

Since human cells carry two copies of each chromosome? they have two versions of each gene?. These different versions of a gene are called alleles?.Alleles can be either dominant? or recessive?.Dominant alleles show their effect even if the individual only has one copy of the allele (also known as being heterozygous?). For example, the allele for brown eyes is dominant, therefore you only need one copy of the 'brown eye' allele to have brown eyes (although, with two copies you will still have brown eyes).

answer; ///(b) it is composed of four protein chains and four heme groups;