Bidirectional DNA replication

FIGURE 25-3 Visualization of bidirectional DNA replication. Replication of a circular chromosome produces a structure resembling the Greek letter theta (0). (a) Labeling with tritium (3H) shows that both strands are replicated at the same time (new strands shown in red). The electron micrographs illustrate the replication of a circular E. coli plasmid as visualized by autoradiography, (b) Addition of 3H for a... 

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