1. A chemical microbiologist, a pathologist and a clown are flying in a small commuter plane between Kansas City and Omaha. Halfway there, the plane bursts into flames and the pilot bails out. The passengers discover there are only two parachutes. Which one dies?

2. 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridinedicarboxylic acid dimethyl ester walks into a bar. On the stools next to it are a leprechaun, a unicorn, and Santa Claus. The bartender has a keg of Guinness, a bag of oats, and a plate of cookies behind the counter. He says to the newcomer, “These three regulars beside you are mean bastards if you screw up their orders – the unicorn will gore you, the leprechaun will steal your soul and Santa Claus will eat your children. Now, I’ve got to step out for a few minutes to make a phone call and I need somebody to watch the bar. $20 says I come back to find you a broken, childless, soulless man.”

1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridinedicarboxylic acid dimethyl ester is always up for a bet and agrees. When the bartender returns, he finds all three of his regulars dead on the floor. Aghast, the barman asks 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-3,5-pyridinedicarboxylic acid dimethyl ester what happened. It replies:

3. Why did the prion get fired from its job at the steel mill?

4. The lac operon is trapped in a room without windows or doors. The walls, the ceiling and the floor are made of steel three feet thick. All it has are a deck of playing cards, a pound of walnuts and a pair of swimming goggles. It can escape three different ways. What are they?

(Originally published on November 20th, 2005)