B3: Cell Division, The Cell Cycle and Sex Determination
Official Cambridge & Imperial ESAT specification requirements for Cell Division, The Cell Cycle and Sex Determination on the Biology paper. Understand the syllabus boundaries, spot distractor traps engineered by examiners, and master the 2-step Sub-90 shortcuts that compress solve time well below the 88.8-second cutoff.
Official Syllabus Subtopics
Requirements specified in the UAT-UK framework
- 1The eukaryotic cell cycle: Interphase (G1 growth, S phase DNA replication, G2 verification) and M phase
- 2Mitosis: prophase, metaphase, anaphase, telophase producing 2 genetically identical diploid (2n) daughter cells
- 3Meiosis: two nuclear divisions producing 4 genetically unique haploid (n) gametes
- 4Sources of genetic variation in meiosis: crossing over (chiasmata) in prophase I and independent assortment of homologous chromosomes in metaphase I
- 5Tracking chromosome number (2n vs n) vs DNA mass (4c ⟶ 2c ⟶ 1c)
- 6Human sex determination: XX female vs XY male (50% probability at fertilisation)
- 7Stem cells: embryonic (totipotent/pluripotent) vs adult (multipotent) stem cell differentiation
Sub-90 Exam Speed Tips
How top candidates solve this spec under the 88.8s clock
Pay close attention to whether a question asks for chromosome number (remains 2n in mitosis, becomes n in meiosis) or DNA mass (doubles during S phase to 4c, then halves).
Independent assortment occurs during metaphase I / anaphase I of meiosis.
Examiners engineer distractor options using common algebraic expansions and sign slips. Always test structural ratios or invariants before calculating arithmetic values.
Tested Topics in Specification B3
Master the individual question patterns and Sub-90 shortcuts for this specification.
Mitosis vs. Meiosis Chromosome (2n/n) & DNA Mass (4c/2c/1c) Tracking + Stem Cell Potency
Track (Chromosomes, DNA mass) as a pair: Somatic G1 = (2n, 2c) -> After S-phase / Metaphase = (2n, 4c) -> Mitosis daughter = (2n, 2c); Meiosis I daughter = (n, 2c); Meiosis II gamete = (n, 1c).
Ready to Master Specification B3 Under Exam Conditions?
Practice timed questions under the authentic Pearson VUE interface with live split stopwatch pacing, dry-wipe scratchpad, and distractor forensics.