... of a freshman biology class - one of almost 600 students, where the students submitted questions to the professor at the first of the year on Index cards and the professor would answer the questions in class throughout the year.

One index card question asked the chemical/biological make-up of sperm.  When the professor finished, a cute blonde in the back raised her hand and asked, "Well, what makes it taste so salty?"  LOL!  She was very popular kid in class after that question!