Practice question

Restriction fragment length polymorphism arises when a point mutation, insertion, or deletion creates or abolishes a recognition sequence, altering cleavage pattern without necessarily altering protein function. Digestion of allelic DNA with the relevant enzyme then yields fragments of differing lengths detectable on agarose gel with altered mobility. No new gene is formed; variation manifests solely as change in band number or size. This principle underlies RFLP-based linkage mapping, forensic DNA fingerprinting, and diagnosis of monogenic disorders like sickle cell anemia, where loss of a site reproducibly changes banding pattern.