Aperson with a phenotype of hbss has sickle cell disease, a person with a phenotype of hbas allele carries the sickle cell trait. a person with a phenotype of hbaa doesn’t have sickle cell disease and doesn’t carry the trait. the punnett square shows the phenotype of two people carrying the sickle cell trait. what are the chances that their offspring will have sickle cell anemia?