GAMSAT cheat sheet

Two essays in 65 minutes total (30 minutes each plus 5 minutes reading); each essay is scored holistically on thought and content, structure and development, and expression, with no penalty for length beyond what time allows.

A defensible thesis states a contestable claim plus a because-clause giving the reason; 'X is important' fails the contestability test, 'X should be prioritised because Y' passes it.

Paragraph architecture: topic sentence naming the claim, evidence or example, analysis linking evidence to claim, then a transition sentence that advances rather than repeats.

Counterargument handling scores higher when the objection is stated in its strongest form, conceded where valid, then bounded by a condition or weighed against a stronger value.

Cohesion devices to deploy deliberately: anaphoric reference (this shift, such reasoning), lexical chains on key terms, and signposting (however, consequently, more importantly) rather than listing (firstly, secondly, lastly).

Register control: avoid absolutes (always, never, everyone) unless defended; replace intensifiers with precise verbs; prefer concrete nouns to abstract nominalisations stacked three deep.

Prompt analysis rule: identify the key term that is ambiguous, define your usage in the introduction, and keep that definition stable across the essay to avoid equivocation.

Timing rule: 3-4 minutes planning, 22-24 minutes writing, 3 minutes checking for agreement errors, comma splices, and pronoun-reference ambiguity.

Correlation versus causation: a observed association supports causation only with temporal precedence, a plausible mechanism, dose-response, and elimination of confounders such as reverse causation or a common cause.

Validity types: internal validity concerns whether the design supports the causal claim; external validity concerns generalisability; a study can be high on one and low on the other.

Selection bias arises when the sample differs systematically from the target population; survivorship bias is its special case where only successful cases remain observable.

Social-theory positions: structural explanations locate cause in institutions and norms; agency explanations locate cause in individual choice; most exam passages reward identifying which level the author privileges.

Utilitarian reasoning aggregates welfare across persons; deontological reasoning constrains acts by duties or rights regardless of aggregate outcome; virtue reasoning asks what a person of good character would do.

Rawlsian veil-of-ignorance test: a rule is just if you would accept it without knowing your position, talent, or endowment under it.

Confirmation bias, anchoring, and framing effects are documented judgement errors; framing changes preference when logically equivalent descriptions are used, so check whether two options are extensionally identical.

Text-interpretation rule: distinguish the author's claim, the evidence offered, and the assumption bridging them; the assumption is usually the unstated premise the question targets.

Dilution: C1V1 = C2V2; a tenfold dilution raises pH of a weak acid buffer only marginally because the ratio of conjugate base to acid, not absolute concentration, sets pH via Henderson-Hasselbalch.

Henderson-Hasselbalch: pH = pKa + log([A-]/[HA]); buffering is strongest within roughly one pH unit of pKa.

Ideal gas: PV = nRT with R = 8.314 J/(mol·K); at constant T and n, P1V1 = P2V2; molar volume at STP (273 K, 100 kPa) is about 22.7 L.

Newtonian mechanics: F = ma, and constant-acceleration kinematics v = u + at, s = ut + 0.5at², v² = u² + 2as; resolve forces along and perpendicular to the incline for ramp problems.

Energy conservation: gravitational potential mgh converts to kinetic 0.5mv²; include friction work (μN·d) as a loss term when surfaces are not ideal.

Genetics: a monohybrid cross of heterozygotes gives 3:1 phenotype and 1:2:1 genotype; a dihybrid cross of double heterozygotes gives 9:3:3:1 when genes assort independently.

Hardy-Weinberg: p + q = 1 and p² + 2pq + q² = 1; allele frequencies stay constant absent selection, drift, migration, mutation, and non-random mating.

Enzyme kinetics: Michaelis-Menten v = Vmax[S]/(Km + [S]); Km is the substrate concentration at half Vmax, and competitive inhibitors raise apparent Km while leaving Vmax unchanged.

Osmosis and tonicity: water moves toward higher solute concentration; a cell in hypertonic solution shrinks, in hypotonic solution swells, and plant turgor depends on cell-wall pressure opposing osmotic inflow.