Question

Discuss the semi-conservative model of replication.

Answer 1

The semi-conservative model of DNA replication explains how a cell makes an exact copy of its DNA before cell division.

• During this process, the double-stranded DNA helix unwinds and unzips as the weak hydrogen bonds between the nitrogenous bases break.
• Each separated strand acts as a template or mould to build a brand-new complementary strand by bringing in free nucleotides matching the base-pairing rules (A pairs with T, C pairs with G).
• When replication is complete, two new identical DNA double helices are formed. Each new DNA molecule contains one original parent strand (conserved) and one newly synthesised strand, which is why it is called semi-conservative.