Subjects include orchids of the British Isles and Operation Mincemeat.

In the first of 24 heats, subjects include Dad's Army and Liverpool FC under Jurgen Klopp.

Subjects include the Mercury Prize, the Marquis de Lafayette and Clara Schumann.

Subjects in the last semi-final include bears and the novels of Dame Muriel Spark.

Subjects include The Stranglers 1974-1990 and Oscar-winning animated feature films.

Semi-final subjects include the history of percussion instruments and Sir Bobby Robson.

Subjects include James I of Scotland, Breaking Bad and the life of Mary Shelley.

Semi-final subjects include the films of Sir Ridley Scott and Genesis from 1967-1977.

This semi-final's subjects include Charlie Chaplin, Happy Valley and Billie Jean King.

Specialist subjects include the human digestive system and The Chemical Brothers.

Subjects include the career of Arsène Wenger, Donny Osmond and The Godfather films.

Subjects include medieval cathedrals of England and Dolly Parton.

Subjects include George Best, Alcibiades and The Rolling Stones.

Subjects include Kim Philby, the castles of north Wales and the life of Thomas Hardy.

Subjects include Leeds United Football Club and Sir Trevor McDonald.

Subjects include British garden birds, The Big Bang Theory and the films of Orson Welles.

Subjects include Meat Loaf, Grinling Gibbons and England women's cricket since 2000.

Subjects include Bridget Riley, the sitcoms of Peter Kay and the history of St Albans.

Subjects include The League of Gentlemen, Nigel Mansell and René Magritte.

Subjects include the New York subway system and the 'Ocean's' films.

Subjects include the films of Martin McDonagh and the music of Tom Waits.

The specialist subjects include Exmoor National Park and the films of Quentin Tarantino.

The specialist subjects include Sir Isaac Newton, Mary Queen of Scots and Billy Bragg.

Subjects include the Salem Witch Trials, Indian Premier League cricket and Edward VIII.

Subjects include Arrested Development and Peter Jackson's The Lord of the Rings trilogy.