AP Practice Test — 50 Questions Across All Subjects

This practice test covers 10 questions from each of Biology, Chemistry, Physics (Mechanics), Calculus, and Statistics — the five most popular AP STEM subjects. The questions follow AP exam style, testing both conceptual understanding and problem-solving. Work through all 50 questions under timed conditions before checking the answer key.

• Time limit: 60 minutes (72 seconds per question)
• Format: Multiple choice — select the best answer from options A–E (AP style)
• Marking: 1 mark per question, 50 marks total
• Conditions: Attempt without notes. Record your answers on a separate sheet.
• After the test: Check the answer key at the bottom. Study the explanations for any questions you got wrong.

Which of the following best describes the function of the rough endoplasmic reticulum?

Correct: B (index 1)

The rough ER is studded with ribosomes and is the site of protein synthesis and initial modification (glycosylation). The smooth ER (A) synthesises lipids. Mitochondria (C) produce ATP. The nucleus (D) is the site of DNA replication.

easy — 1 mark

During oxidative phosphorylation, electrons are passed through the electron transport chain to:

Correct: C (index 2)

In oxidative phosphorylation, electrons are passed along the electron transport chain and ultimately accepted by oxygen, the final electron acceptor, forming water. This creates the proton gradient that drives ATP synthase.

medium — 1 mark

In eukaryotic gene regulation, which of the following is most directly responsible for activating transcription of a specific gene?

Correct: B (index 1)

Transcription factors bind to the promoter region and recruit RNA polymerase, directly activating transcription. Histone acetylation (C) generally facilitates transcription by relaxing chromatin but does not directly activate specific genes.

medium — 1 mark

Which of the following provides the strongest evidence for evolution?

Correct: D (index 3)

All of these provide evidence for evolution. Artificial selection demonstrates that selection produces rapid change. Fossils show gradual transitions. DNA similarities indicate common ancestry. The convergence of multiple independent lines of evidence is what makes evolution so well-supported.

medium — 1 mark

In an ecosystem, the concept of a “trophic cascade” refers to:

Correct: B (index 1)

A trophic cascade occurs when a top predator suppresses the abundance of herbivores, which in turn allows producers to flourish. The classic example is the reintroduction of wolves in Yellowstone, which reduced elk grazing and allowed vegetation recovery.

medium — 1 mark

The renin-angiotensin-aldosterone system (RAAS) regulates:

Correct: B (index 1)

The RAAS is activated when blood pressure drops. Renin triggers the production of angiotensin II, which constricts blood vessels and stimulates aldosterone release, increasing sodium and water reabsorption. This raises blood pressure and restores fluid balance.

medium — 1 mark

A mutation that changes a single nucleotide in a coding region but does not change the amino acid produced is called:

Correct: C (index 2)

A silent mutation changes the DNA sequence but not the amino acid, due to the redundancy of the genetic code. A missense mutation (D) changes one amino acid to another. A nonsense mutation (B) introduces a premature stop codon.

easy — 1 mark

Guard cells regulate the opening and closing of stomata by:

Correct: B (index 1)

Guard cells open stomata by accumulating K+ ions, which lowers their water potential, causing water to enter by osmosis. The cells become turgid and bow apart, opening the pore. When K+ is lost, the cells become flaccid and the pore closes.

medium — 1 mark

Which of the following is characteristic of the adaptive immune response but NOT the innate immune response?

Correct: C (index 2)

Immunological memory is unique to the adaptive immune system. After an initial exposure, memory B and T cells enable a faster, stronger response upon re-exposure. This is the basis of vaccination. All other options are features of innate immunity.

medium — 1 mark

Which of the following is a characteristic of competitive enzyme inhibitors?

Correct: C (index 2)

Competitive inhibitors compete with substrate for the active site, increasing the apparent Km (lowering apparent affinity) without changing Vmax. They can be overcome by increasing substrate concentration. Non-competitive inhibitors decrease Vmax.

medium — 1 mark

Which of the following elements has the highest electronegativity?

Correct: D (index 3)

Electronegativity generally increases across a period and decreases down a group. Chlorine has the highest electronegativity of the listed elements (3.0 on the Pauling scale). Argon, being a noble gas, does not typically form bonds.

easy — 1 mark

In molecular orbital theory, which of the following species is paramagnetic?

Correct: B (index 1)

O2 has two unpaired electrons in its antibonding pi* orbitals, making it paramagnetic. This is one prediction of MO theory that Lewis structures fail to explain. N2 and F2 are diamagnetic.

medium — 1 mark

What volume of 0.10 M HCl is required to neutralise 25.0 mL of 0.20 M NaOH?

Correct: C (index 2)

At the equivalence point, moles of HCl = moles of NaOH: 0.10 x V = 0.20 x 25.0, so V = (0.20 x 25.0) / 0.10 = 50.0 mL.

easy — 1 mark

For a reaction to be spontaneous at constant temperature and pressure, which condition must be met?

Correct: E (index 4)

A reaction is spontaneous when delta G < 0. Since delta G = delta H - T*delta S, the most favourable conditions are delta H < 0 (exothermic) and delta S > 0 (increase in entropy), which always give delta G < 0.

medium — 1 mark

According to collision theory, which of the following will increase the rate of a reaction?

Correct: B (index 1)

A catalyst provides an alternative reaction pathway with a lower activation energy, increasing the rate without being consumed. Lowering temperature (A) and concentration (C) decrease the rate. A larger container (D) decreases concentration.

easy — 1 mark

For the equilibrium 2SO2(g) + O2(g) <=> 2SO3(g), increasing the pressure will:

Correct: B (index 1)

Increasing pressure favours the side with fewer moles of gas. The left side has 3 moles; the right side has 2 moles. Equilibrium shifts to the right to reduce pressure. Kc only changes with temperature.

medium — 1 mark

Which of the following is a buffer solution?

Correct: B (index 1)

A buffer consists of a weak acid and its conjugate base (or a weak base and its conjugate acid). CH3COOH (weak acid) and CH3COONa (its conjugate base) form a buffer. Strong acid + salt (A), strong base + salt (C), and strong acid + strong base (D) are not buffers.

medium — 1 mark

In a galvanic cell, oxidation occurs at the:

Correct: B (index 1)

In both galvanic and electrolytic cells, oxidation always occurs at the anode and reduction at the cathode. Remember: An Ox (anode oxidation), Red Cat (reduction at cathode).

easy — 1 mark

Which of the following is the correct IUPAC name for CH3CH(OH)CH3?

Correct: B (index 1)

The OH group is on carbon 2 of a 3-carbon chain, so the name is 2-propanol (isopropanol). 1-propanol has the OH on carbon 1. Propanal and propanone contain carbonyl groups, not hydroxyl groups.

easy — 1 mark

In beta-minus decay, a neutron in the nucleus is converted into:

Correct: A (index 0)

In beta-minus decay, a neutron converts into a proton and an electron (beta particle). The electron is emitted, and the atomic number increases by 1 while the mass number stays the same. Beta-plus decay produces a positron (B).

medium — 1 mark

A ball is thrown vertically upward with an initial velocity of 20 m/s. Ignoring air resistance, what is the maximum height reached? (g = 10 m/s^2)

Correct: B (index 1)

At maximum height, v = 0. Using v^2 = u^2 - 2gh: 0 = 20^2 - 2(10)h, so 400 = 20h, giving h = 20 m.

easy — 1 mark

A 5 kg object is subject to two forces: 10 N to the right and 3 N to the left. What is the acceleration?

Correct: B (index 1)

Net force = 10 - 3 = 7 N to the right. By Newton’s second law: a = F/m = 7/5 = 1.4 m/s^2.

easy — 1 mark

A 2 kg block slides down a frictionless ramp from a height of 5 m. What is its speed at the bottom? (g = 10 m/s^2)

Correct: B (index 1)

By conservation of energy: mgh = (1/2)mv^2, so v = sqrt(2gh) = sqrt(2 x 10 x 5) = sqrt(100) = 10 m/s.

easy — 1 mark

A 3 kg object moving at 4 m/s collides with a stationary 1 kg object. After the collision, they stick together. What is the final velocity?

Correct: B (index 1)

By conservation of momentum: m1v1 + m2v2 = (m1 + m2)*v_final. (3)(4) + (1)(0) = (4)v_final, so 12 = 4v_final, giving v_final = 3 m/s.

easy — 1 mark

A car of mass 1000 kg travels around a circular track of radius 50 m at a constant speed of 20 m/s. What is the centripetal force?

Correct: C (index 2)

F = mv^2/r = (1000)(20^2)/50 = (1000)(400)/50 = 400,000/50 = 8,000 N.

medium — 1 mark

If the distance between two masses is doubled, the gravitational force between them:

Correct: D (index 3)

By Newton’s law of gravitation, F = Gm1m2/r^2. If r doubles, F becomes Gm1m2/(2r)^2 = Gm1m2/(4r^2) = F/4.

medium — 1 mark

A mass-spring system has a spring constant of 100 N/m and a mass of 0.25 kg. What is the period of oscillation?

Correct: C (index 2)

T = 2pisqrt(m/k) = 2pisqrt(0.25/100) = 2pisqrt(0.0025) = 2pi0.05 = 0.314 s (approximately pi/10).

medium — 1 mark

A solid sphere rolls without slipping down an incline. At the bottom, what fraction of its kinetic energy is rotational?

Correct: A (index 0)

For a solid sphere, I = (2/5)mr^2. With v = omegar (rolling without slipping), KE_rot = (1/2)Iomega^2 = (1/2)(2/5)mr^2*(v/r)^2 = (1/5)mv^2. KE_total = (1/2)mv^2 + (1/5)mv^2 = (7/10)mv^2. Fraction = (1/5)/(7/10) = 2/7.

hard — 1 mark

According to Bernoulli’s principle, where the speed of a fluid increases, the pressure:

Correct: B (index 1)

Bernoulli’s principle states that for an incompressible, non-viscous fluid in steady flow, an increase in speed occurs simultaneously with a decrease in pressure. This explains lift on airplane wings and the curve of a spinning ball.

easy — 1 mark

A double-slit experiment uses light of wavelength 500 nm. The slit separation is 0.1 mm and the screen is 2 m away. What is the fringe spacing?

Correct: C (index 2)

Fringe spacing = lambda*D/d = (500 x 10^-9)(2)/(0.1 x 10^-3) = (10^-6)/(10^-4) = 10^-2 m = 10 mm.

medium — 1 mark

What is the limit as x approaches 0 of sin(x)/x?

Correct: B (index 1)

This is a fundamental limit in calculus. Using L’Hopital’s rule or the squeeze theorem, lim(x->0) sin(x)/x = 1.

easy — 1 mark

What is the derivative of f(x) = x^3 * e^x?

Correct: C (index 2)

Using the product rule: f’(x) = (x^3)’ e^x + x^3 (e^x)’ = 3x^2 e^x + x^3 e^x = e^x(x^3 + 3x^2).

easy — 1 mark

If f(x) = sin(3x^2), what is f’(x)?

Correct: B (index 1)

By the chain rule: f’(x) = cos(3x^2) d/dx(3x^2) = cos(3x^2) 6x = 6x * cos(3x^2).

medium — 1 mark

What is the integral of 2x / (1 + x^2) dx?

Correct: A (index 0)

Let u = 1 + x^2, then du = 2x dx. The integral becomes integral(1/u) du = ln|u| + C = ln(1 + x^2) + C.

medium — 1 mark

What is the definite integral from 0 to pi of sin(x) dx?

Correct: C (index 2)

Integral of sin(x) = -cos(x). Evaluating from 0 to pi: [-cos(pi)] - [-cos(0)] = [-(-1)] - [-1] = 1 + 1 = 2.

easy — 1 mark

For f(x) = x^3 - 3x + 2, at which value of x does f have a local maximum?

Correct: A (index 0)

f’(x) = 3x^2 - 3 = 3(x^2 - 1) = 3(x-1)(x+1). Critical points at x = 1 and x = -1. f”(x) = 6x. f”(-1) = -6 < 0, so x = -1 is a local maximum. f”(1) = 6 > 0, so x = 1 is a local minimum.

medium — 1 mark

A circle’s radius increases at 2 cm/s. How fast is the area increasing when r = 5 cm?

Correct: B (index 1)

A = pir^2. dA/dt = 2pir * dr/dt = 2pi52 = 20 pi cm^2/s.

medium — 1 mark

The volume of the solid obtained by rotating the region under y = x from x = 0 to x = 1 about the x-axis is:

Correct: A (index 0)

V = pi integral from 0 to 1 of (x)^2 dx = pi [x^3/3] from 0 to 1 = pi * (1/3 - 0) = pi/3.

medium — 1 mark

What is the sum of the infinite geometric series 1 + 1/2 + 1/4 + 1/8 + …?

Correct: C (index 2)

This is a geometric series with a = 1 and r = 1/2. Since |r| < 1, the sum = a/(1-r) = 1/(1-1/2) = 1/(1/2) = 2.

easy — 1 mark

Which of the following is the solution to dy/dx = 2y?

Correct: B (index 1)

Separating variables: dy/y = 2 dx. Integrating: ln|y| = 2x + C. Exponentiating: y = e^(2x+C) = e^C * e^(2x) = Ce^(2x).

medium — 1 mark

A data set has values: 2, 4, 4, 4, 5, 5, 7, 9. What is the mean?

Correct: C (index 2)

Mean = (2+4+4+4+5+5+7+9)/8 = 40/8 = 5.

easy — 1 mark

Two independent events A and B have P(A) = 0.3 and P(B) = 0.4. What is P(A and B)?

Correct: A (index 0)

For independent events: P(A and B) = P(A) P(B) = 0.3 0.4 = 0.12.

easy — 1 mark

In a normal distribution, approximately what percentage of data falls within 2 standard deviations of the mean?

Correct: B (index 1)

The empirical rule states: approximately 68% within 1 SD, 95% within 2 SD, and 99.7% within 3 SD of the mean.

easy — 1 mark

Which sampling method is most likely to produce a biased sample of students at a university?

Correct: C (index 2)

A convenience sample uses the most easily accessible individuals, which introduces selection bias. For example, surveying only students in the library excludes those who study elsewhere. Random sampling methods (A, B, D, E) reduce bias.

easy — 1 mark

In a hypothesis test, a p-value of 0.03 means:

Correct: B (index 1)

The p-value is the probability of obtaining results at least as extreme as the observed data, assuming the null hypothesis is true. It is NOT the probability that the null hypothesis is true.

medium — 1 mark

A 95% confidence interval for a population mean is (10, 16). Which interpretation is correct?

Correct: C (index 2)

A confidence interval is about the reliability of the method. A 95% CI means that if we repeated the experiment many times, approximately 95% of the resulting intervals would contain the true population parameter.

medium — 1 mark

In a linear regression model, the coefficient of determination (R-squared) measures:

Correct: B (index 1)

R-squared measures the proportion of the variance in the dependent variable that is predictable from the independent variable(s). An R-squared of 0.85 means 85% of the variation in Y is explained by the model.

medium — 1 mark

In a randomised controlled experiment, the control group:

Correct: B (index 1)

The control group does not receive the experimental treatment and serves as a baseline for comparison. This allows researchers to determine whether the treatment has an effect. The control group may receive a placebo (C), but this is not always the case.

easy — 1 mark

A chi-squared goodness-of-fit test is used to determine whether:

Correct: B (index 1)

The chi-squared goodness-of-fit test compares observed frequencies to expected frequencies to determine whether the data fit a specific distribution. It is used for categorical data.

medium — 1 mark

In hypothesis testing, a Type II error occurs when:

Correct: B (index 1)

A Type I error is rejecting a true null hypothesis (false positive). A Type II error is failing to reject a false null hypothesis (false negative). Reducing one type of error typically increases the other, holding sample size constant.

medium — 1 mark

• AP Biology — Cell biology, genetics, evolution, ecology, and physiology
• AP Chemistry — Atomic structure, bonding, stoichiometry, thermodynamics, and organic chemistry
• AP Physics — Mechanics, energy, momentum, rotation, and oscillations
• AP Calculus AB — Limits, derivatives, integrals, and applications
• AP Statistics — Descriptive statistics, probability, distributions, and hypothesis testing

1. Time yourself. 60 minutes for 50 questions mirrors the pace of the AP multiple-choice section.
2. Use the A–E format. AP exams use five options per question, which reduces the probability of guessing correctly.
3. Study the explanations. AP questions often test common misconceptions — the explanations address these directly.
4. Focus on understanding, not memorisation. AP exams test whether you can apply concepts to new situations.
5. Retake after one week. Spaced repetition is the most effective way to retain information.

Last updated: 24 July 2026

Written by Wyatt. For questions or feedback, visit wyattau.com.