Students are chromosomes.
I played around with the cell division section and thought I would recommend it. It seems like a good way to make sure you have the terminology right. The University of Arizona Biology Project site has an Online Onion Root Tip activity that is very good. The students have to categorize 36 pictures of onion root tip cells in varying stages of the cell cycle. It is a great way to show the kids that at any given time, most cells are in Interphase.