Pattern recognition for the win

[torquill]

Well, I have more faith in my own ability to hit the ground running...

I got to discussion, and yawned through the first fifteen minutes as the TA went over gene multiplication via plasmids. Yeah, I understand restriction enzymes, and how to insert the gene of interest, and multiply it for analysis.

Then she started talking about what would be on the test, and the floor dropped out from under me. Lac and Trp operons, cis and trans, dominant/recessive... I understand the terms, or thought I did, but what the heck is she talking about?

So she does a problem from the book. Great, maybe that will give me some insight. Except that she assumes we've all done it already (did I even touch chapter 10?) and plunges straight into capital letters and + and - signs. I, P, O, Z, Y... C has a subscript C variant, which is constitutively on, but that doesn't tell me what the hell it is. I has its own promoter, but what does it do? And what the heck are Y and Z?

Over the next ten minutes, I pick up what's going on by context. O is the operator, okay. P is the promoter for O. O goes on to transcribe genes Z and Y (aha) so long as it isn't inhibited by the inhibitor protein made by I. Gotcha. There's an I-sup-P which is a super-inhibitor...

There were six scenarios, in which various parts were turned on or off (I-,O+,P+,Z-,Y+ etc) and we had to figure out whether Y and Z were expressed. I didn't pick up the difference between O+ and O- until the last one (+ expresses Y/Z only in the presence of lactose). I had a damned good idea of what was happening by the fourth scenario, though -- given that I was starting from scratch without having heard even the problem first, that impresses me. Cis and trans apparently refer to whether something on one genetic strand can affect the other (inhibitor proteins can drift over, but promoters have to be encoded just before the gene). And dominant/recessive was due to the fact that the TA was using the wrong terms for what was essentially epistasis. Meh.

I'm glad I had plant devel before this -- I would never have understood it otherwise -- but I'm boggled by how fast I picked up the problem without background information. Holy crap.

I don't know how smart that makes me, because no one else I know has been in an easily comparable situation. It seems close to miraculous to me, though... it made sense as I was doing it, but I ended up with a feeling of "how did I just do that?"

It makes me a little more confident when it comes to exams, that's for sure.

Comments

[foogod.livejournal.com]

That reminds me of when I was taking the AP Computer Science test, way back in high school, which was all written in Pascal, which I'd never really used before, and I had to figure out from the program snippet they gave me, using operators no other language uses (up-arrow?? what the heck is that?), that I was working with a linked list, which was a concept I'd never even encountered before that test (and didn't know the name of at the time). And I still answered the question correctly. I was rather proud of that one.

Your case sounded harder, though...

[luna-torquill.livejournal.com]

I would tend to say the opposite -- but then, I have even less programming knowledge than you have genetics knowledge. :)

It's always satisfying to grasp something like that, though. And it does guarantee that what you figure out gets learned thoroughly, given how much brainpower you're bringing to bear on the concepts...