75-Archetype SyllabusBiology • ARCH-B-03 • Spec B3

Full 6-Card Lesson 15-Question Timed Drill

UAT-UK SPEC CODE: B3 (Cell division and sex determination)ASSUMED MATHS 1 PREREQUISITE: M3.5FREQUENCY: VERY HIGH

Mitosis vs. Meiosis Chromosome (2n/n) & DNA Mass (4c/2c/1c) Tracking + Stem Cell Potency

Deconstructed from 35 past UAT-UK questions (15.02% of all historical Biology papers). Students using standard A-Level classroom methods spend an average of 135s on this archetype—blowing past the 90s ESAT budget. Using the 2-line Sub-90 heuristic below compresses solve time to 35s (saving 100s per question).

Historical Frequency

35 Past Qs

15.02% of Biology

Classroom Trap Time

135s

+45s over 90s budget

Sub-90 Target Time

35s

Banks +100s on the clock

Dominant UI Format

Table Matching

Maths 1 Skill: M3.5

Card 1 & Card 2 Preview: The Classroom Time Trap vs. Sub-90 2-Line Rule

Excerpted from our interactive 6-Step Topic Lesson for ARCH-B-03.

Launch All 6 Active-Recall Cards

CARD 1 OF 6 • THE CLASSROOM TIME TRAP (135s)

Why Students Bleed Time:

Start from the G1 somatic baseline

(2n = 78, 2c = 6.0\text{ pg})

. After S-phase replication, a cell enters Metaphase at

(2n = 78, 4c = 12.0\text{ pg})

. Mitosis yields

(2n = 78, 2c = 6.0\text{ pg})

; Meiosis I yields

(n = 39, 2c = 6.0\text{ pg})

; Meiosis II yields gametes at

(n = 39, 1c = 3.0\text{ pg})

. Thus the target stage has

39

chromosomes and

3.0\text{ pg}

of DNA (~120s).

In 35 past UAT-UK questions (15.02% of Biology), candidates lose 100s by dna mass doubles (2c -> 4c) during s-phase, making each chromosome 2 sister chromatids, but chromosome count (centromeres) stays 2n = 46 until anaphase. Instead, apply B3 with Maths 1 skill M3.5.

CARD 2 OF 6 • THE 2-LINE SUB-90 HEURISTIC (<35s)

Line 1 (Pair Tracker): G1

= (78, 6.0) \xrightarrow{\text{S}} (78, 12.0)

Line 2 (Target Stage): mature sperm cell (after Meiosis II)

= (39\text{ chromosomes}, 3.0\text{ pg DNA})

(25s).

Sanity & Limit Check: Verify units/signs against factor_of_two_or_stoichiometry_trap (Saying chromosome number doubles from 46 to 92 during S-phase DNA replication) and fence_post_or_domain_trap (Reporting somatic diploid DNA mass (2c) as the gamete DNA mass (1c), or G2 replicated mass (4c) as normal G1 mass (2c)).

Examiner Distractor Blueprint for ARCH-B-03

FOIL #1factor_of_two_or_stoichiometry_trap

Saying chromosome number doubles from 46 to 92 during S-phase DNA replication

DNA mass doubles (2c -> 4c) during S-phase, making each chromosome 2 sister chromatids, but chromosome count (centromeres) stays 2n = 46 until anaphase.

Open Factor-of-2 / Stoichiometry Clinic

FOIL #2fence_post_or_domain_trap

Reporting somatic diploid DNA mass (2c) as the gamete DNA mass (1c), or G2 replicated mass (4c) as normal G1 mass (2c)

Failing to track the 2c (G1) -> 4c (S/G2/Metaphase I) -> 2c (after Meiosis I) -> 1c (haploid gamete after Meiosis II) sequence.

Open Fence-Post / Domain Trap Clinic

FOIL #3multi_statement_linchpin_foil

Confusing pluripotent embryonic stem cells (all body tissues except extra-embryonic placenta) with totipotent zygote/morula cells or multipotent adult bone marrow stem cells

Swapping stem cell potency hierarchy: Totipotent (zygote, all cells + placenta) > Pluripotent (embryo, all body tissues) > Multipotent (adult bone marrow, restricted lineage).

Open Multi-Statement Linchpin Foil Clinic

FOIL #4table_column_pruning_trap

Reading long stage descriptions before pruning table rows via Haploid (n) vs Diploid (2n) chromosome count

Checking n vs 2n eliminates half the rows in 3 seconds.

Open Table Column Pruning Trap Clinic

Try 1 Live Sample Question Under the 90-Second Stopwatch

Press W to open the 2-line dry-wipe scratchpad, select A–E, and lock in to reveal the Dual-View solution.

Full 6-Card Lesson Launch All 15 Questions (ARCH-B-03)

ARCH-B-03: Mitosis vs. Meiosis Chromosome (2n/n) & DNA Mass (4c/2c/1c) Tracking + Stem Cell Potency (Sample)Biology

00:00.0

SUB-90 ZONE (<35S)

0.0s35s Sub-9090s ESAT Budget150s Classroom

Question 1 of 1ARCH-B-03 (6-Card Lesson)Format: Standard 5-Option

Right-click any option to cross out • Keys A–E + Enter

Question 1 of 1 • 90s Target

Ready to Start Question 1?

The question stem, diagram, and answer options are hidden behind this pre-start gate. When you click below, the question will reveal and your 90-second split stopwatch will immediately begin ticking.

Biology•ARCH-B-03•Standard 5-Option

or press Enter to start