When John Cairns first visualized the replication of E.coli chromosomes in 1963 what did he conclude? 1.The chromosomes of E.coli are circular structures that exist as u-shaped intermediates during replication.
2)The unwinding of the two complementary parental strands and their semiconservative replication occur simultaneously or are closely coupled.
3)Semiconservative replication of the E.coli chromosome started at a specific site,and proceeded sequentially and unidirectionally around the circular structure