Beyond the answers - interesting background to this quiz

A Baltic capital shaped by trade and technology

Tallinn, the capital of Estonia, sits directly on the Gulf of Finland, which is part of the Baltic Sea. Its well-preserved medieval old town is a major draw for visitors, but the city is also known for a strong digital sector. Estonia has built a reputation for e-government services, and many international tech companies have chosen Tallinn as a base for their operations in Northern Europe.

Why South Korea's currency is called the won

The South Korean won takes its name from the same linguistic root as the Chinese yuan and the Japanese yen - both originally meaning something round, like a coin. The won was reintroduced in South Korea in 1962, replacing the hwan. Banknotes feature notable figures from Korean history and culture, while coins range from small denominations up to 500 won.

The whale shark - a giant that eats tiny prey

The whale shark is the largest living fish, and the largest shark species in the world. Despite its enormous size, it is a filter feeder, swimming with its wide mouth open to collect plankton, small fish and other tiny organisms. Whale sharks are found in warm tropical and subtropical waters, and they are known for their distinctive pattern of pale spots and stripes on a dark background.

Colombia's share of the Amazon

Colombia is one of several South American countries covered by the Amazon Rainforest, along with Brazil, Peru, Ecuador, Bolivia, Venezuela, Guyana, Suriname and French Guiana. In Colombia, the Amazon region occupies the southern part of the country and is far less densely populated than the Andean and Caribbean zones. The forest there is home to an extraordinary range of plant and animal life, much of it still being documented by scientists.

The heart's role in circulation

The heart is a muscular organ that pumps blood through the circulatory system, delivering oxygen and nutrients to tissues and carrying away waste products. In humans it beats roughly 60 to 100 times per minute at rest, though that rate varies with fitness, age and activity. The right side of the heart sends blood to the lungs to pick up oxygen, while the left side pumps oxygen-rich blood out to the rest of the body.