D3.2.11—Sex determination
Sex determination in humans depends on X and Y chromosomes, with sperm determining whether the zygote is XX or XY.
- Syllabus
- First assessment 2025
- Objective
- D3.2.11
- Level
- SL
Exam analysis
Chance of appearing2%of analysed past papers
Latest appearanceMay 2023
Most common paperPaper1
Typical marks1–3
Common command terms
- Identify
- Explain
Recent exam appearances
May 2023Paper2 ["SL"] · TZ16(c)[ 3 ]D3.2.11—Sex determination
November 2014Paper1 ["SL"] · TZ017[ 1 ]D3.2.11—Sex determination
May 2014Paper1 ["SL"] · TZ130[ 1 ]D3.2.11—Sex determination
Practice this objective
Coverage 2014–2023 · Updated 16 Jul 2026
Concept essentials
- Eggs normally contribute an X chromosome.
- Sperm may contribute either an X or a Y chromosome.
- The sperm chromosome determines whether the zygote is XX or XY.