D2.1.5—DNA replication prerequisite
DNA replication in S phase creates sister chromatids that remain attached until their separation during mitosis or meiosis later in division.
- Syllabus
- First assessment 2025
- Objective
- D2.1.5
- Level
- SL
Exam analysis
Chance of appearing2%of analysed past papers
Latest appearanceMay 2024
Most common paperPaper1
Typical marks1
Common command terms
- Distinguish
Scoring notes
- Common mistake
- Counting chromosomes and chromatids as the same thing after DNA replication.
Recent exam appearances
May 2024Paper2 ["SL"] · TZ12(a)(ii)[ 1 ]D2.1.5—DNA replication prerequisite
May 2017Paper1 ["SL"] · TZ15[ 1 ]D2.1.5—DNA replication prerequisite
May 2017Paper1 ["SL"] · TZ214[ 1 ]D2.1.5—DNA replication prerequisite
Practice this objective
Coverage 2017–2024 · Updated 16 Jul 2026
Concept essentials
- DNA replication occurs in S phase of interphase.
- After replication, each chromosome consists of two sister chromatids.
- Sister chromatids remain joined at the centromere before separation.
- DNA amount doubles from G1 to G2 before division.