UAT-UK SPEC CODE: B7 (Variation, selection and evolution)ASSUMED MATHS 1 PREREQUISITE: M7.7FREQUENCY: MEDIUM
Natural Selection, Antibiotic Resistance, Heterozygote Advantage & Speciation Sequence Foils
Deconstructed from 7 past UAT-UK questions (3% of all historical Biology papers). Students using standard A-Level classroom methods spend an average of 120s on this archetype—blowing past the 90s ESAT budget. Using the 2-line Sub-90 heuristic below compresses solve time to 30s (saving 90s per question).
Historical Frequency
7 Past Qs
3% of Biology
Classroom Trap Time
120s
+30s over 90s budget
Sub-90 Target Time
30s
Banks +90s on the clock
Dominant UI Format
1-2-3 Statement
Maths 1 Skill: M7.7
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-13.
CARD 1 OF 6 • THE CLASSROOM TIME TRAP (120s)
Why Students Bleed Time:
In Darwinian natural selection applied to antibiotic resistance:
1. Random mutation generates a resistance allele spontaneously (independent of whether the antibiotic is present) (1 is correct).
2. Selection pressure: Methicillin kills non-resistant cells, so resistant cells survive, reproduce, and pass the allele (via vertical binary fission or horizontal plasmid conjugation) to offspring (2 is correct).
3. Bacteria never mutate 'in order to' survive exposure (3 is incorrect).
1. Random mutation generates a resistance allele spontaneously (independent of whether the antibiotic is present) (1 is correct).
2. Selection pressure: Methicillin kills non-resistant cells, so resistant cells survive, reproduce, and pass the allele (via vertical binary fission or horizontal plasmid conjugation) to offspring (2 is correct).
3. Bacteria never mutate 'in order to' survive exposure (3 is incorrect).
In 7 past UAT-UK questions (3% of Biology), candidates lose 90s by mutations occur randomly and spontaneously before exposure; the antibiotic acts purely as an environmental selection pressure that kills non-resistant individuals. Instead, apply B7 with Maths 1 skill M7.7.
CARD 2 OF 6 • THE 2-LINE SUB-90 HEURISTIC (<30s)
Mutations are random/pre-existing (1), antibiotic is the selection pressure (2), never Lamarckian 'mutate to survive' (eliminate 3) 1 and 2 only.
Mutations are random/pre-existing (1), antibiotic is the selection pressure (2), never Lamarckian 'mutate to survive' (eliminate 3) 1 and 2 only.
Sanity & Limit Check: Verify units/signs against
multi_statement_linchpin_foil (Lamarckian foil: claiming exposure to an antibiotic or pesticide CAUSES the resistance mutation to occur so the organism can survive) and multi_statement_linchpin_foil (Claiming humans develop immunity to antibiotics (instead of bacteria evolving antibiotic resistance)).Examiner Distractor Blueprint for ARCH-B-13
FOIL #1multi_statement_linchpin_foil
Lamarckian foil: claiming exposure to an antibiotic or pesticide CAUSES the resistance mutation to occur so the organism can survive
Mutations occur RANDOMLY and spontaneously BEFORE exposure; the antibiotic acts purely as an environmental selection pressure that kills non-resistant individuals.
FOIL #2multi_statement_linchpin_foil
Claiming humans develop immunity to antibiotics (instead of bacteria evolving antibiotic resistance)
Bacteria—not human host cells—evolve resistance to antibiotics via random mutation and natural selection.
FOIL #3fence_post_or_domain_trap
Saying continuous variation (height, mass) is controlled by a single gene without environmental influence (which describes discontinuous variation like ABO blood group)
Discontinuous variation = single/few genes, distinct categories, no environmental effect; Continuous variation = polygenic + environment, normal distribution.
FOIL #4sign_or_direction_flip
Ordering the Darwinian natural selection cascade with 'adaptation/selection' before 'random mutation and genetic variation'
Strict sequence: (1) Random mutation creates new allele/variation -> (2) Selection pressure / competition -> (3) Advantageous phenotype survives -> (4) Reproduces and passes on allele -> (5) Allele frequency increases over generations.
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.
sub90 ESATARCH-B-13: Natural Selection, Antibiotic Resistance, Heterozygote Advantage & Speciation Sequence Foils (Sample)Biology
00:00.0
SUB-90 ZONE (<30S)
0.0s30s Sub-9090s ESAT Budget150s Classroom
Right-click any option to cross out • Keys
A–E + EnterQuestion 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-13•Standard 5-Option
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