One possible approach: assert that chess is strongly linked to EVERY SUBJECT on the curriculum. Have a slide prepared for any subject they might ask about. Then challenge them to name any subject that IS NOT strongly linked to chess.
Suppose they say: ...
religion. Put up the slide with some key items from Bill Wall's article http://www.chess.com/article/view/religion-and-chess (be nice to contact him first)
sport. Chess has been an acredited Olympic sport - it's not at the moment. It probably will be again. (batgirl knows a lot about it.) Also chess-boxing: about the most extreme combination of physical & mental sports.
dance. The musical 'Chess' by Andrew Lloyd-Webber.
history. Modern chess is ~500 years old. Derived from ancient Indian/Persian games. See Wikipedia.
politics. Bobby Fischer's role in overcoming the Soviet Union's dominance at the height of the Cold War. http://www.greenleft.org.au/2004/583/32473
French. French terms used in chess: en passant, j'adoube. French Opening.
biology. Men tend to be better at chess than women. Make sure you can back this up with solid results from the Net!
chemistry. Chess pieces are made from many different materials http://www.chess.com/forum/view/more-puzzles/wood-you-believe-it
physics. Richard Feynman talking about learning chess as an analogy for understanding nuclear physics http://www.youtube.com/watch?v=o1dgrvlWML4
And so on for ... geography, music, art, mathematics, cookery, woodwork, music, English Lit. ...
Keep it simple and add some humor.