Question

marla is a known carrier of the sickle - cell allele, while jerry is unsure of his genotype. the couple have three children, and one is diagnosed with sickle - cell disease (scd). what is jerrys genotype? hb^a/hb^a hb^s/hb^s hb^a/hb^s there is not enough information to tell

Explanation:

Sickle - cell disease is an autosomal recessive disorder. A carrier has the genotype $Hb^A/Hb^S$. Since one of their children has SCD (genotype $Hb^S/Hb^S$), each parent must have contributed a $Hb^S$ allele. Marla is a carrier ($Hb^A/Hb^S$). So Jerry must also have a $Hb^S$ allele to pass on to the affected child.

Answer:

$Hb^A/Hb^S$