Beyond the answers - interesting background to this quiz

The sea that shaped a region's identity

Latvia is one of nine countries with a Baltic Sea coastline, alongside Estonia, Lithuania, Poland, Germany, Denmark, Sweden, Finland and Russia. The sea has long served as a trading highway between Scandinavia and the eastern Baltic, and it remains one of the least salty bodies of water on Earth because so much fresh water flows in from rivers. That low salinity is why many typical ocean species cannot survive there.

A novel that took years to finish

Fyodor Dostoevsky published "The Brothers Karamazov" in 1880, less than a year before his death. He wrote it as a serial, and it was intended as the first part of a larger work that he never completed. The novel explores faith, doubt and patricide through the three Karamazov brothers, and it is often cited as one of the finest achievements in Russian literature.

The tiny structures that power our cells

Mitochondria generate most of the chemical energy that cells use, in the form of ATP. They have their own DNA, separate from the DNA in the nucleus, and this is inherited only from the mother. That unusual feature is why mitochondrial DNA is widely used to trace maternal ancestry.

Europe's highest peak and the debate around it

Mount Elbrus, in the Caucasus range of southern Russia, rises to 5,642 metres and is generally considered the highest mountain in Europe. Some geographers place the Europe-Asia boundary further south, which would hand the title to Mont Blanc instead. The disagreement is really about where Europe ends - a question maps have never fully settled.

When Austria traded its schilling for the euro

Austria used the schilling until 2002, when euro coins and notes entered circulation across much of the European Union. The schilling had been the country's currency since the 1920s, apart from a period after the Second World War. Its replacement was part of the euro's physical launch, one of the largest currency changes in history.