ASIC200 Science-y questions for the final exam.

I’ll follow suit with Allen’s previous post about the sort of questions that might be thrown at you for the science portion of the ASIC200 final exam.

Essentially, the science section will be about 6 short answer questions done within a timeframe of about 1 hour. Both topics (climate change and GMOs will be on the agenda) The basic premise is that the first will be pretty easy, with the second getting a little tougher and so on. As well, it is my intention that if you study the notes well, 4 out of the 6 questions will be eminently doable – in fact like a lot of science final exams, if you really know your stuff, it would actually take you far less time than the one hour to complete (This is why at your usual 3 hour chemistry, physics or biology exams, you alway see these students handing in their papers after an hour. Generally speaking these are the students who have kicked ass on the exam – damn them!)

The last two science questions, I’m actually going to try and design it so that the answer is not immediately obvious. i.e. you’ll have to look at things a little more conceptually to get at the answer. Anyway, below are four examples of the kind of questions you can expect, the last one here being more in the conceptual vein.

1. Can you define “climate” and explain how the term is different from “weather.”

2. DNA polymerase plays a key role in replication. In terms of their function, they adhere to two steadfast biochemical rules. What are these two rules?

3. You’ll note that by looking at this graph of temperature change according to layer of atmosphere, the stratosphere goes from hot to cold as you lose altitude. Can you explain why?

4. In class it was mentioned that the human genome has upwards of 97% of its code being non-functional or junk DNA. Bacteria on the other hand tends to not have any non-functional or junk DNA. Can you hypothesize why we (as humans) would have so much filler or useless DNA?

ANSWERS?

Well, the first three should be pretty straightforward if you peruse through the lecture notes. The last, however, takes a bit more thought, because the answer doesn’t technically exist (and certainly isn’t something I specifically went over in class). However, I’d be looking here for a good hypothesis that could explain why so much of “your” DNA appears to have no function (as compared to the e.coli example).

Answers could range from:

“Maybe we just think it’s non-functional, and haven’t discovered what it’s doing yet.” Not a great answer, because it would imply that there must be a hugely fundamental difference between bacteria and us – so fundamentally different that we can’t decipher at all what it is doing. i.e. whilst a possible hypothesis, there really isn’t a good argument for it (other than we’re still ignorant), although depending on the strength of your rebuttal of why we could be easily ignorant about such things you could still score on this question.

“We’re high maintenance, as compared to e.coli. We exist due to many cell divisions that act in a nuanced convoluted way. For crying out loud, it takes 9 months for us to even get out into the world. This means we want to protect ourselves from errors in the code as much as possible. One mechanism to do this is to dilute our genome with a high amount of places where errors are inconsequential. E.coli don’t have that because it’s no big deal if one of them messes up – these suckers duplicate themselves every 20 minutes. Mutations in the grand scheme of things is o.k. with e.coli. For us, mutations could be catastrophic for something so high maintenance and constantly in progress.”

“Maybe the 97% has something to do with how the good stuff is physically organized. i.e. Not all genes are used by each and every cell, so there needs to be a mechanism to allow certain genes to be accessible, whilst others are hidden or not allowed to be used. Maybe this 97% has something to do with this – it’s a question of controlling the architecture of that big old piece of DNA.” In other words, the 97% may be non-functional from a coding context, but happen to play a different role.

Anyway, hope these examples help…