Practice question

Genetic distance quantifies meiotic recombination probability not physical DNA length. Alfred Sturtevant defined arbitrary map unit as one percent crossover between markers later named centimorgan honouring Thomas Hunt Morgan. Physical distance measured in base pairs or nanometers reflects double helix length while centimorgan reflects exchange frequency varying with chromatin structure hotspot distribution and interference. Two genes recombining in one percent meioses lie one centimorgan apart allowing construction of linkage maps where additive distances approximate chromosome organisation though correlation to base pairs varies significantly across genome.