An Hfr strain that is met+pro+bio+his+ was mated with an F- strain that was met-pro-bio-his-. Mating was interrupted and the percentage of cells with each phenotype was determined by replica plating the cells on minimal media plates that lacked met, pro, bio or his. The data shown in Figure 1 were obtained. During conjugation, cells gain genes in the order they occur in the donor cell chromosome. Genes that are near the origin of transfer will be transferred first. Use the graph to help you construct a map of the four genes. (Figure 2) Drag the genes onto the map in the proper order. Minutes 10 12 15 20 Percentage Percentage Percentage Percentage of cells with of cells with of cells with of cells with bio his met pro phenotype phenotype phenotype phenotype 7 0 0 2 25 15 3 20 40 28 42 17 35 25 Solution Answer: Origin - met+ - his+ - pro+ - bio+ Explanation: As we know that during conjugation, cells gain genes in the order they occur in the donor cell chromosome. Genes that are near the origin of transfer will be transferred first. From the graph it is clear that met+ gene transfer first and goes on increasing its percentage as time passes. so it is present closest to the origin. Then his+ gene shows more percentage transfer than pro+ gene and atlast bio+ gene transfers..