It's called DNA replication. It is the process of copying the DNA molecule resulting into 2 new DNA strands.This process is important for every individual's genes, identity and heredity. 
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The point where the double helix is opened up and the DNA is copied iscalled a replication fork. Once the strands are separated, an enzymecalled DNA polymerase copies each strand using the base-pairing rule. The two strands are not exactly copied the same way
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