Mixed Deck — All A-LEVEL Topics Flashcards

What is the key feature that distinguishes an experiment from a correlational study?

Answer: Manipulation of an independent variable to observe its effect on a dependent variable

The defining feature of an experiment is the deliberate manipulation of an independent variable (IV) while measuring its effect on a dependent variable (DV), with control of extraneous variables. Correlational studies only measure the relationship between co-variables without manipulation.

What is the role of oestrogen in controlling the menstrual cycle?

Answer: At low concentrations it inhibits LH/FSH; at high concentrations it stimulates the LH surge that triggers ovulation; it also repairs the uterine lining

Oestrogen has complex feedback effects: at low levels it negatively feeds back to inhibit FSH/LH. At high levels near ovulation, it provides positive feedback triggering the LH surge. It also repairs and thickens the endometrium after menstruation.

What is dramatic irony?

Answer: When the audience knows something that the characters on stage do not

Dramatic irony occurs when the audience possesses knowledge that characters lack, creating tension or humour. In 'Romeo and Juliet', the audience knows Juliet is not truly dead, making Romeo's suicide deeply tragic.

What is a buffer solution and how does it resist pH change?

Answer: A solution that resists changes in pH when small amounts of acid or alkali are added, typically containing a weak acid and its conjugate base

A buffer contains a weak acid (HA) and its conjugate base (A⁻, from a salt). Adding acid: A⁻ + H⁺ → HA (base removes excess H⁺). Adding alkali: HA + OH⁻ → A⁻ + H₂O (acid neutralises OH⁻). pH change is minimal.

What is the difference between elastic and inelastic collisions?

Answer: Elastic collisions conserve both momentum and kinetic energy; inelastic collisions conserve momentum but not kinetic energy (some KE is lost as heat or sound)

In elastic collisions, kinetic energy and momentum are both conserved (e.g., billiard balls). In inelastic collisions, momentum is conserved but kinetic energy is not — some is converted to heat, sound, or deformation.

El Niño is associated with which of the following ocean and atmospheric conditions?

Answer: Unusually warm sea surface temperatures in the central and eastern Pacific Ocean

El Niño is characterised by unusually warm sea surface temperatures in the central and eastern Pacific Ocean, which disrupts normal atmospheric circulation and weather patterns globally.

What is 'collective cabinet responsibility' in the UK?

Answer: All Cabinet ministers must publicly support government decisions once made, or resign — this maintains unified government

Collective cabinet responsibility means all Cabinet members must publicly support government policy regardless of their private views. If they cannot, they must resign (e.g., Robin Cook over Iraq, 2003). This maintains government unity and accountability.

What is the difference between nationalism and patriotism?

Answer: Patriotism is love and pride in one's country; nationalism is a political ideology that asserts the nation should be self-governing, and may involve belief in the superiority of one's nation over others

Patriotism is an emotional attachment to one's country. Nationalism is a political ideology claiming nations should be sovereign and self-determining. Nationalism ranges from civic/inclusive forms to ethnic/exclusive forms; extreme nationalism can lead to xenophobia or conflict.

What is Euler's formula: e^(iθ) = ?

Answer: cos θ + i sin θ

Euler's formula states e^(iθ) = cos θ + i sin θ. At θ = π, this gives e^(iπ) + 1 = 0 (Euler's identity). It links complex numbers, exponentials, and trigonometry in one elegant equation.

A circle has equation x² + y² - 6x + 4y - 12 = 0. What is its radius?

Answer: 5

Completing the square: (x-3)² + (y+2)² = 9 + 4 + 12 = 25. So the radius is √25 = 5.

What is 'historiography' and why does it matter in A-Level History?

Answer: The study of how historians have interpreted and debated historical events; engaging with it shows awareness of differing scholarly perspectives

Historiography is the study of historical writing and interpretation. In A-Level essays, referencing historians' views (e.g., 'Fischer's thesis on German war guilt' vs. 'revisionist views') demonstrates deep engagement with the discipline and earns higher marks.

What is the derivative of f(x) = x⁴ − 3x² + 5x − 2?

Answer: 4x³ − 6x + 5

Using the power rule: d/dx(xⁿ) = nxⁿ⁻¹. d/dx(x⁴) = 4x³, d/dx(−3x²) = −6x, d/dx(5x) = 5, d/dx(−2) = 0. So f'(x) = 4x³ − 6x + 5.

In 'Macbeth', what does Lady Macbeth's obsessive hand-washing in Act 5 symbolise?

Answer: Her guilt and psychological torment over the murders

The hand-washing is a powerful symbol of guilt. Lady Macbeth, who earlier dismissed guilt ('A little water clears us of this deed'), is now consumed by it. The irremovable 'spot' represents the permanent stain of moral corruption.

What is the Hardy-Weinberg principle?

Answer: A model stating that allele frequencies in a population remain constant from generation to generation in the absence of evolutionary influences

The Hardy-Weinberg principle states that allele and genotype frequencies remain constant in large, randomly mating populations with no mutation, migration, selection, or genetic drift. Equations: p + q = 1 and p² + 2pq + q² = 1.

In George Orwell's 'Animal Farm', the pigs gradually becoming indistinguishable from humans is an example of which literary device?

Answer: Allegory

Animal Farm is an allegory for the Russian Revolution and the rise of Stalinism. The pigs represent the Communist Party leaders, and their transformation into human-like figures allegorises how revolutionary leaders became indistinguishable from the oppressors they replaced.

What is 'counterurbanisation'?

Answer: The movement of people from urban areas into rural or suburban areas

Counterurbanisation is the process by which people and businesses move out of urban centres into surrounding rural or suburban areas, often enabled by improved transport and remote working.

What is a demand characteristic in psychological research?

Answer: A cue in the study that leads participants to guess the aim and alter their behaviour accordingly

Demand characteristics are cues in the experimental situation that convey the hypothesis to participants, potentially leading them to change their behaviour (e.g., through the 'please-u' effect or screw-you effect). This threatens internal validity.

The equation x² + 6x + k = 0 has no real roots. Which inequality must k satisfy?

Answer: k > 9

For no real roots, the discriminant b² - 4ac 36, giving k > 9.

What is the 'multiplier effect' in economic geography?

Answer: The way in which one economic investment generates further economic activity and jobs

The multiplier effect describes how an initial investment or job creation generates additional economic activity as money circulates through the local economy, creating further employment and income.

What is a nucleophile?

Answer: An electron-pair donor — a species rich in electrons that attacks electron-deficient (δ+) carbon atoms

A nucleophile is an electron-rich species that donates an electron pair to an electron-deficient atom. Common nucleophiles include OH⁻, CN⁻, NH₃, and halide ions. They attack δ+ carbons in polar covalent bonds.