Agene is composed of two alleles. an allele can be either dominant or recessive. suppose that a husband and wife, who are both carriers of the sickle-cell anemia allele but do not have the disease, decide to have a child. because both parents are carriers of the disease, each has one dominant normal-cell allele (s) and one recessive sickle-cell allele (s). therefore, the genotype of each parent is ss. each parent contributes one allele to his or her offspring with each allele being equally likely. complete parts a) through c) below. a) genes are always written with the dominant gene first. therefore, there are two instances the offspring could have genotype ss (one if the mother contributes the dominant allele and the father contributes the non-dominant allele; and one if the father contributes the dominant allele and the mother contributes the non-dominant allele). list the other two possible genotypes of the offspring.   nothing