Practice question

Given SDS frequency 40 percent among ordered octads scored in Neurospora, gene-centromere recombination equals half that value because only half chromatids recombinant per SDS tetrad with two parental two recombinant configuration. Therefore distance equals 20 percent or 20 centimorgans, representing moderate linkage to centromere. Calculation steps: percent SDS = number SDS asci divided total asci ×100 =40, then half =20 cM final distance. This distance lies within typical centromere-proximal to intermediate region demonstrating measurable linkage. Knowledge allows ordering genes relative centromere and predicting proportion FDS asci expected nearby.