# Explain why DNA replication is described as semi-conservative and outline the significance of this mechanism for inheritance.

> IB DP Biology Higher Level (2023 syllabus) — D1.1 DNA replication · Explain · 4 marks

## Mark scheme (4 marks)

1. Each new double helix contains one original (parental) strand and one newly synthesised strand
2. The parental strand acts as a template, with complementary base pairing directing the sequence of the new strand
3. The base sequence of the parental DNA is faithfully reproduced in both daughter molecules, preserving genetic information
4. Semi-conservative replication ensures that heritable information is transmitted unchanged across cell generations / underpins genetic continuity

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