I went to UCSF interview last year, and yes, you are given an essay question. The topic was not hard at all, but I struggled with writing the essay by hand. I stopped writing things by hand 15 years ago!!!! I am used to typing essays on the computer (organizing main ideas, editing by copy/cut/paste, etc) that when I was given a piece of paper and a pen to write an essay, I was STRUGGLING. Plus, I couldn't even write legibly. Practice writing on a plain sheet of paper. That should help.