How is DNA replicated when a cell divides?

The DNA in the parent cell is made up of two strands. We know that each daughter cell needs to contain two strands with the same information after DNA replication. There are three ways we could produce these identical copies of DNA:a) conservatively: after one replication, one daughter cell contains two associated parent strands, the other contains two associated "new" strands. b) semi-conservatively: the strands of the parent cell split and are used as templates for new strands. This produces DNA where one strand is from the parent cell, and one strand is newly synthesised. The parent and daughter cells both contain DNA which is one strand new, one strand parental.c) dispersive: after replication, the strands are a mixture of parental and daughter DNA.
DNA is replicated semi-conservatively. The main steps are as follows:1) Unwinding of the double helix by a helicase enzyme. The helicase breaks hydrogen bonds between complementary bases in the polynucleotide strands.2) This allows new DNA nucleotides to pair with exposed bases on single stranded template DNA strands. This complementary base pairing allows the newly synthesised double stranded DNA to be identical to the original parent DNA, so each cell has the same information after replication. 3) A DNA polymerase enzyme is responsible for joining the new nucleotides onto the elongating strand.
If the student wishes, this question allows further exploration e.g. Meselson and Stahls evidence for semi-conservative replication, the details of the replication fork, differences btwn eukaryotes/prokaryotes or discussion of mutation and how it is linked to errors during replication.