a geneticist is studying a pedigree that shows the family history of a recessive genetic diease. which of the following pedigrees shows an impossible relationship.

None of the above.

To determine which pedigree shows an impossible relationship, the geneticist needs to analyze the inheritance pattern of the recessive genetic disease in question. The pedigree chart is a visual representation of the family's genetic history. It includes information about affected individuals (those who have the disease), unaffected individuals (those who don't have the disease), and the relationships among them.

To identify an impossible relationship within a pedigree, the geneticist should look for patterns that violate the known rules of genetic inheritance.

Recessive genetic diseases are typically inherited in an autosomal recessive manner, meaning that both copies of the gene must be altered (recessive) for an individual to show signs of the disease. In this case, unaffected individuals can carry one altered copy of the gene, known as a carrier.

When analyzing the pedigree, the geneticist should look for situations where unaffected individuals have affected children without having any affected ancestors.

It would be helpful to see the provided pedigrees to give a specific answer to your question.