I did a chemistry degree. (I still do a chemistry degree, just now I'm a PG.)
We had to run our NMR spectra of molecules we made (it's basically a way of identifying what you've made. It comes out as a graph mapping signal response (y axis) to frequency (x axis) (kind of, that's a massive simplification)), and I lost mine this one week.
I was fucking pissed with myself, but then I came up with a cunning plan.
Our labs were staggered, because the whole of our year couldn't fit into any one lab. So I went to the draw were our scripts are put after marking, and found one that hadn't been picked up yet. It was pretty shit, had more of the markers annotations than his own work, somehow he managed a D+. I took it to the library, scanned in his spectra, photo-shopped out all the annotations and pretty much redrew them on accounting for all the markers corrections.
I picked up the script a week later. I scored an A, and I turned to the NMR spectra. All it said was 10, ie perfect marks for that question.
All was well, until the next lab. A TA came up to me and said something like 'you're pretty good at annotating NMR spectra, aren't you. Almost as good as me', then walked away leaving me looking stunned.
Moral of the story: TA's always know. Good TA's let you get away with it.