2012 USABO Thread

<p>note: equilibrium doesn’t mean equal concentrations; equilibrium means that there is no net change in products/reactants any longer</p>

<p>@darksigma: thanks for the help. I get it now!</p>

<p>guys, i have 3 questions in cliffs second test:
<a href=“http://i49.■■■■■■■.com/5ywb9i.jpg[/url]”>http://i49.■■■■■■■.com/5ywb9i.jpg&lt;/a&gt; why is the answer in this one D? I solved it E. Shouldn’t a parasite live on the host? If it laid its eggs on it or something, isn’t that a parasitoid?
and <a href=“http://i50.■■■■■■■.com/2rraq07.jpg[/url]”>http://i50.■■■■■■■.com/2rraq07.jpg&lt;/a&gt; I don’t get any of this one lol
and this is the title for the question: <a href=“http://i45.■■■■■■■.com/4qg7c3.jpg[/url]”>http://i45.■■■■■■■.com/4qg7c3.jpg&lt;/a&gt; and the question itself: <a href=“http://i45.■■■■■■■.com/sl3ckz.jpg[/url]”>http://i45.■■■■■■■.com/sl3ckz.jpg&lt;/a&gt; why is the answer E and not A?</p>

<p>for #89: A and E are worded similarly. An important difference is in keywords: “close” vs. “statistically significant”.</p>

<p>“close” is a loose term so we choose something more solid and relevant to statistics.</p>

<p>Hey Guys! Congrats to everyone that participated, it is very tough competition. I will be participating next year as a sophomore. I have bought Campbells 9th, Inquiry into Life 13, Modern Genetic Analysis, Raven’s Biology, Raven’s Biology of Plants, Voet Biochemistry, Lehninger Biochemistry, Albert’s Molecular Biology of the Cell, and Life: the Science of Biology by Purves. How should I tackle this? I have little experience with Bio, but I really like it. I am highly motivated. I will be taking a college Bio course this summer and AP Biology next year. I will also be using Yale 122 and MIT OCW to prepare. How many hours of preparation will be necessary to conquer this. I want to make Finals this year.</p>

<p>^ I think the answer is clear: as many as you can. If you have free time, study. If you want to browse the internet, resist the urge and study. The more you study, the better you’ll do.</p>

<p>@JasonJackson789 For #9 it’s E because the pulmonary arteries go to the lungs and come back through pulmonary veins. When they talk about the double bed capillaries, they are saying the oxygenated blood diffusing around the body. (idk if your getting this xD) But the capillaries are between the arteries and veins right? but the lung is an exception because they don’t give oxygen to cells. More like they give oxygenate the blood. The double bed capillaries are start from the aorta and come back to the heart from either the superior or posterior vena cava. (Idk if I explained this well xD sorry if you can’t understand )</p>

<p>LOL I just realized that post was from like 2 weeks ago xD My bad. I also ordered Raven and campbell. But I took AP bio this year and didn’t know about the exam. I am probably going to take the USABO USPhyO and the USNCO next year. What a GREAT SUMMER (sarcasm) Any good sites to help study.(practice tests, more info, etc.)</p>

<p>Wow Daesung that is tough. I think you should take them all, but focus mainly on one of them. I would either focus on Bio/Chem or Physics/Chem. As for web resources, you can mainly find practice tests. A link is somewhere on this thread.</p>

<p>bump,</p>

<p>As somebody famous put it:</p>

<p>“If you like to memorize the endless bits and pieces of biological info then study Bio.
If you you prefer to understand why it is not a good idea trying to run into a brick wall then study Physics.
But if you simply enjoy being a detective and would like to hone your knowledge, logic, intuition and common sense while having fun solving Chemistry problems, then National Chemistry Olympiad could be the right choice for you.”</p>

<p>@daesung
Old exams for Chem Olympiad are here. Depending on your school/region one needs to score somewhere in the range of 50-56 to get to National exam.
[Chemistry</a> Olympiad Exams](<a href=“American Chemical Society”>American Chemical Society)</p>

<p>the topics covered on Chemistry Olympiad exams follow closely AP Chem. But much broader knowledge is needed to make the team.</p>

<p>@chemtutor: i would disagree with ur comments re the bio oly, but to each is his own :P</p>

<p>A couple of the questions from the list of sample questions from prior IBOs: <a href=“http://www.ibo-info.org/rules-syllabus/syllabus/sample-questions[/url]”>http://www.ibo-info.org/rules-syllabus/syllabus/sample-questions&lt;/a&gt;&lt;/p&gt;

<p>1 (IBO 2001 – B4)<br>
Match each item in column A with one in column B to which it is most closely associated.
Column A Column B
A. leucoplasts 1. Krebs cycle
B. rough ER 2. bacterial DNA anchorage
C. genome 3. microtubule-organizing center
D. mitochondria 4. protein modification and targeting
E. centriole 5. complete set of genetic instructions
F. mesosome 6. starch storage
G. lysosome 7. immunoglobulin
H. microfilament 8. lipid synthesis
I. smooth ER 9. digestive enzymes </p>

<p>4 (IBO 2002 – B3)
Calculate the intracellular millimolar (mM) concentration of potassium in Escherichia coli, if
the measured potassium content is 7.8 micrograms per milligram of dry cell mass. Assume
all potassium ions are free in the cytosol (not bound to macromolecules), and that the
intracellular volume is 2 microlitres per milligram of dry cell mass. The atomic weight of
potassium is 39 Daltons.</p>

<p>These are not hard questions.</p>

<p>@chemistry tutor: not exactly sure re: the point ur trying to make with the above post, but these are the “easy” questions. If you took a look at some of the other biology olympiad exams in more detail, you’ll see that there are also much more difficult questions…</p>

<p>just don’t want to spread misconceptions lol</p>

<p>@ChemistryTutor:" As somebody famous put it:</p>

<p>“If you like to memorize the endless bits and pieces of biological info then study Bio.”</p>

<p>I completely disagree. Biology has come a long way from just memorization and regurgitation. Molecular Biology is very analytical and most research work in science is going to require knowledge of Biology. Statements like this will make smart students fear Biology and that is a terrible loss for science.</p>

<p>Is there a similar group for USACHO?</p>

<p>^ Yes. It’s on the HSL subforum.</p>

<p>Can you post a link? Thanks.</p>

<p>@Opinion559
<a href=“http://talk.collegeconfidential.com/high-school-life/1297600-official-2012-usnco-chemistry-olympiad-discussion-23.html?highlight=olympiad[/url]”>http://talk.collegeconfidential.com/high-school-life/1297600-official-2012-usnco-chemistry-olympiad-discussion-23.html?highlight=olympiad&lt;/a&gt;&lt;/p&gt;