Beyond the answers - interesting background to this quiz

The race to the double helix

The discovery of DNA's double helix in 1953 is usually credited to James Watson and Francis Crick, whose short paper in Nature relied heavily on X-ray diffraction images produced by Rosalind Franklin and Maurice Wilkins at King's College London. Franklin's famous Photo 51 was central to revealing the molecule's helical shape, yet her contribution went largely unacknowledged for decades. Watson, Crick and Wilkins shared the Nobel Prize in 1962; Franklin had died of cancer four years earlier, and the prize is not awarded posthumously.

Ninety minutes and the referee's watch

A football match is nominally 90 minutes, split into two halves of 45, but the clock does not stop for injuries, substitutions or celebrations. The referee adds stoppage time at the end of each half, which is why matches routinely run past the 90-minute mark. Competition rules sometimes alter the format entirely: extra time, penalty shootouts and, in some youth or small-sided games, shorter halves altogether.

One river, many countries

The Mekong begins on the Tibetan Plateau and runs roughly 4,300 kilometres through China, Myanmar, Laos, Thailand, Cambodia and Vietnam before emptying into the South China Sea. Its lower basin supports one of the world's most productive inland fisheries, and the river's seasonal flood pulse is essential to farming and fishing communities along its banks. Dams upstream, particularly in China and Laos, have changed that rhythm in ways scientists continue to study.

Bishkek and the Tian Shan backdrop

Bishkek, the capital of Kyrgyzstan, sits at the foot of the Tian Shan mountains in the Chuy Valley, close to the border with Kazakhstan. It was renamed several times during the twentieth century, reflecting the region's shifting political history under Russian and Soviet rule. Today it is one of Central Asia's larger cities and a common starting point for travellers heading into the country's alpine lakes and trekking routes.

A planet with a lopsided path

Mercury has the most eccentric orbit of the eight planets, meaning its distance from the Sun varies more than any other planet's. At its closest it lies roughly 46 million kilometres from the Sun; at its farthest, about 70 million. That uneven path, combined with a slow rotation, produces extreme temperature swings between the planet's sunlit and shadowed sides.