Beyond the answers - interesting background to this quiz

The sitcom role that made a hairstyle famous

Jennifer Aniston played Rachel Green on Friends, a role that turned her into one of the most recognisable faces on television in the 1990s. Rachel's layered cut, soon nicknamed "the Rachel", became one of the most requested hairstyles in salons of the era, even though Aniston herself has said she found it hard to maintain. The show ran for ten seasons and followed six friends through life and love in New York City.

A sea with no coastline in the ocean

The Caspian Sea is the largest inland body of water on Earth, bordered by five countries including Russia, Iran and Kazakhstan. Although it is called a sea, it has no connection to the ocean and sits between Europe and Asia. Its water is brackish rather than fully salty, and it is rich in sturgeon, the fish behind some of the world's most prized caviar.

A fight for independence remembered in Texas

The siege of the Alamo took place in San Antonio, Texas, in 1836, during the Texas Revolution against Mexican rule. A small group of defenders held the mission for around two weeks before it fell. Among those who died was Davy Crockett, already a folk hero in the United States. "Remember the Alamo" later became a rallying cry for Texan independence.

Carbon, the element behind life itself

Carbon's chemical symbol is simply C, and it sits at the heart of organic chemistry. Every known living thing contains carbon, which bonds easily with other elements to form an enormous variety of molecules. Its close neighbours on the periodic table, such as calcium (Ca) and potassium (K), are often confused with it by students.

The planet with a crowded sky

Jupiter has the most confirmed moons of any planet in the Solar System, with the count continuing to rise as astronomers discover smaller ones. Its largest moons, including Ganymede, are big enough to be studied in detail. Saturn is not far behind, which is why the two gas giants regularly trade places in news headlines about moon counts.