Ecology Quiz: Climate, Energy and Oceans
Ecology quiz: greenhouse effect, CO2, the 3 Rs, renewable energy, the ozone layer, the Paris climate deal, biodiversity, deforestation, oceans and composting.
Historical events, figures, key dates
The History theme travels through the major periods of the past, from prehistory to the present day: the French Revolution and Napoleon, the Renaissance and the Age of Discovery, the two world wars, the Cold War and the fall of the Berlin Wall, along with figures such as Louis XIV, Joan of Arc, Christopher Columbus or Winston Churchill. Questions mix key dates, causes and consequences, treaties and famous names.
If you want to brush up on the classics or fill a few gaps, these history quizzes can be played at no cost: five difficulty levels from very easy to expert, and a comment after each answer to place the event in context. Neighbouring themes such as Antiquity and the Middle Ages let you dig deeper into one particular era.
Ecology quiz: greenhouse effect, CO2, the 3 Rs, renewable energy, the ozone layer, the Paris climate deal, biodiversity, deforestation, oceans and composting.
Astronomy quiz: solar system planets, the Moon, stars, black holes, Galileo, Kepler, Hubble, James Webb and exoplanets. Test your space knowledge.
Expert ecology quiz: Milankovitch cycles, CO2 warming calculated in 1896, The Tragedy of the Commons, Gaia and the Brundtland Report.
A hard ecology quiz: the wetlands convention, the IPCC's creation year, nitrate and phosphate pollution, what CITES regulates and mangroves.
Intermediate ecology quiz: acid rain pollutants, ozone-depleting compounds, the Rio Earth Summit, the Kyoto adoption year and the Paris Agreement talks.
Easy ecology quiz: the greenhouse gas from livestock, the Kyoto Protocol, photosynthesis by-products, geothermal energy and coral bleaching.
A very easy ecology quiz: the greenhouse gas from fossil fuels, a renewable energy, photosynthesis, the largest rainforest and the 3Rs rule. 10 questions.
Expert geology quiz: the mantle-core boundary, the solid inner core's discoverer, Tambora's 1815 eruption, peridotite's mineral and the Mesozoic periods.
Expert computer science quiz on the RSA inventors, binary search complexity, The Art of Computer Programming, Ruby's creator and Unix's birthplace.
A hard geology quiz: the crust-mantle boundary, number 1 on the Mohs scale, the first seismic waves, the great Krakatoa eruption and the liquid core.
A hard computer science quiz: the first programmer, the Internet's ancestor, the lab behind C, IPv4 address size and the imitation game. 10 questions.
Intermediate geology quiz: what quartz is made of, the layer between crust and core, the seismograph, how marble forms and where new oceanic crust appears.
Intermediate computer science quiz: the inventor of the World Wide Web, the Linux kernel's creator, SQL, binary 1010 and the S of HTTPS. 10 questions.
Easy geology quiz: main rock types, the earthquake magnitude scale, underground molten rock, an ancient supercontinent and the hardest mineral.
Easy computer science quiz: who founded Microsoft with Paul Allen, a snake-named language, what HTML does, the CPU acronym and bits in a byte.
A very easy geology quiz: molten rock flowing from a volcano, moving plates and earthquakes, what a rock is, the Earth's core and a volcano's opening.
A very easy computer quiz: the cursor device, the maker of the iPhone, web browsers, where the @ symbol is used and what USB stands for. 10 free questions.
Expert math quiz: the proof of Fermat's Last Theorem, the Poincaré conjecture, Platonic solids, Euler's formula for polyhedra and the golden ratio.
A hard math quiz on a derivative, a base-10 logarithm, summing 1 to 100, the diagonals of a hexagon and Euler's famous identity. 10 questions.
Intermediate math quiz: the value of pi, a first-degree equation, a circle's area, a factorial and the hypotenuse of a 3-4 right triangle. 10 questions.
Easy math quiz on a square's perimeter, powers of 2, the sum of a triangle's angles, the square root of 144 and spotting a prime number. 10 questions.
Very easy math quiz of mental arithmetic: an addition, a multiplication, a subtraction, half of 50 and the sides of a triangle. 10 free questions.
Intermediate medicine quiz: the oxygen-binding blood protein, Pasteur's 1885 vaccine, the smallest bone, the scurvy vitamin and the discovery of X-rays.
Expert medicine quiz: the inner ear's hearing structure, the pineal gland's hormone, insulin's 1921 co-discoverer, Rosalind Franklin's Photo 51 and myelin.
A hard medicine quiz: blood circulation described in 1628, Koch's 1882 bacterium, antibody-making cells, a long cranial nerve and the A, B, O blood groups.
Easy medicine quiz: ABO blood groups, the 1928 penicillin discovery, the insulin organ, the bone protecting the brain and the first smallpox vaccine.
A very easy human body quiz: the organ pumping blood, the breathing organs, an adult's bone count, the thinking organ and the largest organ. 10 questions.
Expert astronomy quiz: a white dwarf's mass limit, black hole radiation predicted in 1974, standard-candle supernovae and a rival theory to the Big Bang.
A hard astronomy quiz on accelerating expansion, galaxies moving apart in 1929, black holes, the 1965 radiation and gravitational waves. 10 questions.
Intermediate astronomy quiz: the 16th-century heliocentric model, the region beyond Neptune, collapsed stars, a galactic collision and planetary laws.
Easy astronomy quiz on the first Moon walk in 1969, Earth's rocky neighbor, Pluto's status since 2006, Jupiter's moons and polar auroras. 10 questions.
Very easy astronomy quiz: the star at the heart of our solar system, the planet nearest to it, the Moon and tides, constellations and ringed planets. Free.
Expert biology quiz on gene regulation without DNA change, the CRISPR-Cas9 system, the origin of mitochondria, chromosome ends and programmed cell death.
A hard biology quiz on gamete production, the enzyme unwinding DNA, the 1953 double helix, extreme-trait selection and chlorophyll in plants. 10 questions.
Intermediate biology quiz: how cells make energy from glucose, the vertebrate skeleton, sexual reproduction, the thyroid and antibody-making immune cells.
Easy biology quiz: the molecule of genetic information, cells without a nucleus, the cell's powerhouse, universal blood donors and cell division.
A very easy biology quiz: which organ lets us breathe, a spider's legs, the largest mammal, the organ we think with and frogs. 10 free questions.
Expert physics and chemistry quiz: fermions and quantum states, Schrödinger's equation, mass conservation, electron energy levels and photon energy.
A hard physics and chemistry quiz on quantum uncertainty, the Higgs particle found at CERN, entropy, the 1869 periodic table and the neutron. 10 questions.
Intermediate physics and chemistry quiz: the symbol Na, electrical energy units, the three laws of motion, a toxic combustion gas and the nucleus.
Easy physics and chemistry quiz on the speed of light, the Curies and radioactivity, atoms, heat-releasing reactions and the acidity scale. Free.
Very easy physics and chemistry quiz: the symbol for oxygen, water's boiling point, the apple and gravity, states of matter and Earth's pull. 10 questions.
The war began in 1914, after Archduke Franz Ferdinand of Austria was assassinated in Sarajevo on 28 June. Alliances between the great powers drew Europe into the conflict within weeks, and it ended with the armistice of 11 November 1918.
On 14 July 1789, Parisians stormed the Bastille, a royal fortress used as a prison that symbolised arbitrary royal power. The event marks the start of the French Revolution, and Bastille Day became France's national holiday in 1880.
The Berlin Wall, built in 1961 to stop people leaving East Germany for the West, fell on the night of 9 November 1989 when the border crossings were opened. It paved the way for German reunification, which became official on 3 October 1990.