Question

1. which of the following is the best example of a possible future technology that could be used to eliminate sickle cell disease in humans? a. a genetically engineered virus which can eliminate sickle - shaped cells in human blood b. genetic screening which matches sickle cell carriers to people with aa genotypes c. the ability to replace all s alleles in human red blood cells d. the ability to replace all s alleles in fertilized eggs

Explanation:

Sickle - cell disease is a genetic disorder caused by a mutated allele (S). Eliminating the S allele at the source, which is the fertilized egg, would prevent the disease from developing in future individuals. Option A only targets existing sickle - shaped cells, not the root genetic cause. Option B is about matching carriers and does not eliminate the disease. Option C is not feasible as red blood cells have no nucleus and cannot have their alleles replaced. Option D addresses the genetic origin of the disease by replacing the S alleles in fertilized eggs.

Answer:

D. the ability to replace all S alleles in fertilized eggs