Timed mating was carried out with the strains described belo

Timed mating was carried out with the strains described below and the resulting cells were placed on the various media. The table below summarizes the analysis of these matings. What is the order of the gly, pro, lac and Ais genes on the E.coli chromosome. Choose the best answer. glyu, pro, his, lac pro, gly, his, lac pro, his, lac, gly gly, lac is likely not linked to the other three genes.

Solution

The nearest gene to selective marker will be having highest linkage and will come in highest frequency and lesser frequency genes will be subsequently farther.

So the sequence is pro-gly-his-lac in the order of linkage.

The answer is b)pro, gly, his, lac