Beyond the answers - interesting background to this quiz

The dive that outpaces a speeding car

The peregrine falcon is not just the fastest bird - it is the fastest animal on the planet. In a hunting dive, known as a stoop, it folds its wings tight against its body and drops at speeds that can exceed 300 km/h. That speed is paired with remarkable eyesight: a peregrine can spot prey from more than a kilometre away. On the level, its normal cruising flight is far slower, which makes the stoop all the more spectacular.

A sea with a misleading name

The Red Sea separates northeastern Africa from the Arabian Peninsula, stretching from the Suez Canal down to the Gulf of Aden. Its name has puzzled observers for centuries - the water is usually a deep blue-green, though blooms of certain algae can tint its surface reddish-brown. The sea sits in a rift valley where two tectonic plates are slowly pulling apart, which helps explain its unusual depth and its warm, salty water.

Florence and the birth of the Renaissance

Florence, in the Italian region of Tuscany, is widely regarded as the cradle of the Renaissance. The city's wealth, built on banking and trade, funded artists and thinkers such as Leonardo da Vinci, Michelangelo and Dante, who was born there. Walk through its historic centre today and you are moving through the same streets that shaped European art and ideas for centuries.

The lake that holds a fifth of the world's fresh water

Lake Baikal in Siberia is the deepest lake on Earth, reaching more than 1,600 metres at its lowest point. It is also the oldest, estimated at around 25 million years, and holds roughly a fifth of the planet's unfrozen fresh water - more than all the North American Great Lakes combined. Its isolation has produced thousands of species found nowhere else, including the freshwater Baikal seal.

Why carrots and night vision share a history

Vitamin A is essential for vision, particularly in low light, because the retina uses a form of it to build the pigment that lets our eyes register dim images. A severe deficiency can lead to night blindness, which is why the vitamin has long been linked to eyesight in popular culture. The idea that carrots specifically sharpen vision, however, was popularised during the Second World War as a cover story for British radar technology - a myth that outlived its original purpose.