<p>siRNA would not be a viable way of measuring mRNA expression. I put microarray but I can’t remember if I put RT-PCR or not. In either case I think microarray and RT-PCR are the answers.</p>
<p>Also, did the question before that only ask for steps to make a viable cloning vector? I didn’t include transformation and etc. steps after that b/c I didn’t think that was suppose to be part of the answer, since technically the ‘cloning vector’ is the plasmid itself and not the bacterium carrying the plasmid.</p>
<p>We learned a lot about siRNA in AP Biology!!!:D</p>
<p>@1nkbl0tch: weird, I talked to the 2008 siemens second place winner today who did a project on alternative RNA splicing, and she said siRNA and microarray would be the right answers…so now I dont know who to believe anymore lol.</p>
<p>was that one where you had to get all the answers in order to be counted correct?
i’m almost positive that RT-PCR counts as a viable method, i spent pretty much my entire summer doing RT-PCR protocols for measuring gene expression. it would be kinda dumb if USABO says it doesnt work lol</p>
<p>Wow, now I’m extremely confused as well. If siRNA were introduced, wouldn’t the expressed mRNA be degraded after being tagged by the siRNA? Also, I haven’t heard of siRNA being used to detect whether a gene is being expressed. It’s usually used to silence genes to study its functions by observing abnormalities that arise after it’s gone.</p>
<p>From U of Miami website:
"Today RNA interference (RNAi), is a technique in which exogenous, double-stranded RNAs (dsRNAs) that are complimentary to known mRNA’s, are introduced into a cell to specifically destroy that particular mRNA, thereby diminishing or abolishing gene expression. The technique has proven effective in Drosophila, Caenorhabditis elegans, plants, and recently, in mammalian cell cultures.</p>
<p>Thus, RNA interference (RNAi), is a gene-silencing technique used in studying the absence of normal gene action (by disrupting its activity in vivo, i.e., turning it off) in fruit flies, nematodes, and mammalian cells. "
(<a href=“http://fig.cox.miami.edu/~cmallery/150/gene/siRNA.htm[/url]”>http://fig.cox.miami.edu/~cmallery/150/gene/siRNA.htm</a>)</p>
<p>RT-PCR still seems to be the right answer. Here’s one of many research papers involving mRNA expression measured by RT-PCR:
<a href=“joe-sub”>joe-sub;
<p>The first sentence is “We have used quantitative RT-PCR to analyse the mRNA expression profile of the major components of the IGF axis in different stages of murine mammary gland development”</p>
<p>On the bright side, at least we all agree that microarray is an answer :D</p>
<p>Haha, yeah microarray definitely. I’m also not sure on how siRNA would help measure gene expression because usually doesn’t it repress gene expression? I think RT-PCRs are probable because it deals with cDNA which essentially HAVE to be expressed since they’ve been transcribed into RNA first. Thus, if you do RT-PCR, you measure the amount that is amplified from the cDNA, which is an indicator of how much of a particular gene was expressed in the first place.</p>
<p>It was on the first FR problem…if we circled siRNA then we get no points for that part?</p>
<p>Wow, a thriving thread about USABO!
This makes me glad. 
Good luck, guys!</p>
<p>
Go with Lodish! I warn you, I am very much biased in my answer though - I work, like, 20 meters away from the guy, and I have two friends who work for him!</p>
<p>Yeah, Lodish is beast, 80% of the book’s authors work at MIT lol</p>
<p>What’s the name of the text by Lodish?</p>
<p>This year’s semis murdered me, because of the molec. bio concentration. Had it been biochem or something like that, I could have done better. Plus, the conditions that I took the test under weren’t exactly ideal…</p>
<p>really? I was under the impression that 50% of the test was ecology. Especially part C… it was like YES! MOLECULAR BIOLOGY! <em>flips page</em> CRAP! ECOLOGY! <em>flips page</em> CRAP! ECOLOGY!</p>
<p>For the seed dispersal question, I could only think of 3 ways that seeds spread: wind, water, animal. I thought of “explosion”, but then decided against it b/c it sounded rather ■■■■■■■■. I mean… seed dispersal by explosion?</p>
<p>Then I went online and searched “seed dispersal”… up comes:
- water
- wind
- animal
- explosion</p>
<p>I slapped myself.</p>
<p>Edit: The one I have by Lodish is “Molecular Cell Biology, 5th ed.”</p>
<p>I probably got only 60% of the seed dispersal question, for some reason I kept thinking the mechanisms had to have a scientific name O_O</p>
<p>I thought the test had a LOT of molecular biology, lol (then again, 45 % of the syllabus basically is molecular biology)</p>
<p>wow…explosion. X_X I put animal twice cause one for eating the thing and one for carrying it on their bodies.</p>
<p>that’s EXACTLY what I did as well :</p>
<p>I managed to convince myself only fungi dispersed spores by explosion… even though the question was asking about SEEDS. Now that I look back on it I cringe at my stupidity…</p>
<p>Yea i put animals down twice for that too</p>
<p>Yeah, now that I think closely about it, it should have been explosion because some seeds really do that. </p>
<p>I think I’ll just try to not think about whether I made it or not until I get the phone call from Marcy…IF I even manage to get a phone call.</p>
<p>I got a call today!!! I came home at 5:30 today, and there was this message on my phone. It started off w/ “Hello, this is Marcy Reedy…” and for a second there I thought it was a commercial (i’m stupid), but then it went on to say “I’m from the center for excellence for education…”. And that was the point where I dropped everything I was holding and started screaming.</p>
<p>I didn’t think they call you this early, since scores don’t come out until next Monday. Good luck everyone! :]</p>
<p>congrats! well u are #1 in the country…good job, i am jealous :)</p>
<p>Oh wow, nice…I guess I didn’t make it haha.</p>
<p>Well, supposedly there are still phone calls tomorrow…</p>