Beyond the answers - interesting background to this quiz

The science with the least glamorous name

Botany comes from the Greek word "botane", meaning pasture or herb, and it is simply the branch of biology concerned with plants. It covers everything from the structure of a single leaf cell to the ecology of entire forests. Related fields such as mycology (fungi) and microbiology (microscopic organisms) are sometimes lumped in with it, but botanists traditionally keep their focus on the plant kingdom.

Thirteen days that brought the world to the brink

The Cuban Missile Crisis unfolded in October 1962, when American reconnaissance flights revealed Soviet nuclear missiles on Cuban soil. President John F. Kennedy responded with a naval "quarantine" of the island, and for several tense days the two superpowers edged towards direct conflict. The standoff ended when the Soviet Union agreed to withdraw its missiles in exchange for a US pledge not to invade Cuba and the quiet removal of American missiles from Turkey.

A planet wrapped in carbon dioxide

Mars is often called the Red Planet because of the iron oxide dust that coats its surface, but its atmosphere is just as distinctive. Roughly 95 per cent of it is carbon dioxide, with only traces of nitrogen and argon. That thin, CO₂-rich air is a major reason the planet is so cold and why any human mission would need elaborate life-support systems.

Variations that became a showpiece

Sergei Rachmaninoff wrote his "Rhapsody on a Theme of Paganini" in 1934, casting it as a set of 24 variations for piano and orchestra. The work is built on a famous violin caprice by Niccolò Paganini, and its 18th variation - a lush inversion of the original theme - has become one of the most recognisable pieces in the classical repertoire. Rachmaninoff himself premiered the piece as soloist, cementing his reputation as both composer and virtuoso pianist.

A river that crosses a continent

The Orinoco rises in southern Venezuela near the Brazilian border and flows roughly 2,140 kilometres before emptying into the Atlantic Ocean. Along the way it splits into a vast delta of channels and islands, and its basin supports an extraordinary range of wildlife, including river dolphins and the Orinoco crocodile. For much of its length it remains a lifeline for communities and ecosystems far from any major city.