Must be joined together by DNA ligase to make continuous DNA strand. So can replicate the whole chromosome in half the time if only unidirectional synthesis. Second round of DNA replication is initiated long before first round is finished. In exponential growth, cells can accumulate 1 or two rounds of DNA before division occurs. View bidirectional replication in DNA , with multiple initiation sites.
Cells can spend more energy repairing DNA than synthesizing it.
Will discuss later. Also proofreading is necessary. When new DNA is synthesized, occasional errors in base pairing occur. If not corrected, could lead to mutations, loss of functions, loss of competitiveness, evolutionary weeding out. Can be spontaneously lost over time unless some selection makes plasmid valuable to cell.