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In a double-stranded DNA molecule, the strands are antiparallel to each other and replicate simultaneously at the advancing replication fork. DNA polymerase enzymes help the replication in $5\text{'}$ $→$ $3\text{'}$ direction only. One strand can be synthesized continuously while the other is replicated by creating Okazaki fragments.

In E.coli, one strand of newly synthesized DNA contains 1000-2000 nucleotides long Okazaki fragments. The genome length of Escherichia coli is about $4.6×{10}^6$base pairs.

For the entire replication of the E. coli genome, the number of Okazaki fragments required is:

No. of Okazaki fragments = Total length of the genome of the E.coli

Length of each Okazaki fragment

When the length of the Okazaki fragment is 1000 base pairs,

No. of Okazaki fragments = $4.6×{10}^6$base pairs$=$$4600$

$1000$ base pairs

When the length of the Okazaki fragment is 2000 base pairs,

No. of Okazaki fragments =$4.6×{10}^6$base pairs $=$ 2300

$2000$ base pairs