I think this is a great teachable moment:

Scientists complete genome sequence of fungus responsible for dandruff, skin disorders from PhysOrg.com
Scientists from P&G Beauty announced that they successfully sequenced the complete genome for Malassezia globosa (M. globosa), a naturally occurring fungus responsible for the onset of dandruff and other skin conditions in humans. Results of the genome sequencing are published in today’s online edition of Proceedings of the National Academy of Sciences.[…]

I mean, think about it. Kids in biology class have a hard time relating to size and scale. You can show them stuff in a microscope, but that is not really a tiny thing, is it? I mean,a microscope is like a funny looking TV that you’ve got to get really close to in order to see something that, compared to real TV, is rather boring.But to think about the idea that Malassezia globosa … a species of fungus … is a tiny invisible thing you never knew was there, living on your head, causing your dandruff, and that it has a whole genome … over four thousand genes.I think what works with this is the following: Tiny things visualized in microscopes or on computer screens have a tininess making them invisible, and a bigness (the microscope, the computer screen) making them visible. But the dandruff causing fungus has an intermediate size scale that we can relate to because we can see it, scratch it, brush it off our shoulders … the actual dandruff flakes.Hey, if you are a teacher, try it out in class and see if it works!