Following a discussion about geological age: "So is it like the layer that's closest to the air is newer? Like what's touching the air? It seems like the top layer should be the oldest because that's where they find dinosaur bones."

In Biology after a discussion about evolution: "So where do people with different skin colors come from...like black people?"
"Where does Spanish come from?"

"Is the protein that's in protein shakes the same kind that's in your body?"

If there's two things that don't mix like oil and water, it's tools and school. Especially when it's science. "Tool" is a colloquialism that needs very little clarification, however, some of the contributors at www.urbandictionary.com had this to add:
"A person, typically male, who says or does things that cause you to give them a 'what-are-you-even-doing-here' look. The 'what-are-you-even-doing-here' look is classified by a glare in the tool's direction and is usually accompanied by muttering of how big of a tool they are. The tool is usually someone who is unwelcome but no one has the balls to tell them to get lost. The tool is always making comments that are out-of-place, out-of-line or just plain stupid. The tool is always trying too hard to fit in, and because of this, never will. However, the tool is useful because you can use them for things; money, rides, etc."
I would add that a tool generally wears white-rimmed sunglasses, drives a lifted truck, has most of their wardrobe confined to "affliction" or "monarchy" brand clothes, has bleached highlights in their hair, and can usually be found at the gym lifting weights or tanning or buying protein shakes.
When my wife and I began taking college science courses, we couldn't help but notice the couple of tools who provided comedic relief during the boredom of Biology and Chemistry. We've enjoyed their comments so much we decided to share them.