Practice question

Recombination frequency quantifies probability of exchange between two loci measured as proportion recombinant progeny. Exchange probability depends on physical length of DNA, chromatin structure, and map distance, not on how alleles are distributed across homologs in the parent. Cis AB/ab and trans Ab/aB both possess identical interlocus chromatin and identical chance of chiasma formation. Arrangement merely defines which gametes are labeled parental versus recombinant after meiosis in testcross. After correcting labeling, calculated RF identical because crossover mechanism occurs independently of allelic phase, reflecting conserved chromosome biology.