DNA polymerases synthesize new DNA only in the 5′→3′ direction. Because the parental strands are antiparallel, one new strand can be synthesized continuously toward the replication fork, whereas the other is synthesized discontinuously in fragments away from the fork and later joined. The lagging strand is not synthesized 'backward'; both new strands are made 5′→3′.
ADNA polymerase can only add nucleotides in the 5′→3′ direction
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