Genetic Testing And Diagnostics Practice Test

In a molecular genetics laboratory, a technician is preparing a labeled, single-stranded DNA molecule. This molecule is designed to be complementary to a specific gene sequence on a chromosome. It will be used in an experiment to visualize the location of that gene within a cell nucleus.

A geneticist is studying a large family affected by a rare, autosomal dominant form of early-onset dementia. The causative gene is unknown. To identify the chromosomal location of the gene, the researcher genotypes all family members, both affected and unaffected, for hundreds of polymorphic DNA markers spread across the genome. The goal is to find markers that are consistently inherited along with the disease.