2012 USABO Thread

<p>yes it was b3</p>

<p>For the carnivorous plants, the one that was false is that it traps insects for energy. Energy is derived purely from photosynthesis. The carnivorous lifestyle is merely for extracting nitrogen.</p>

<p>Every post darksigma writes makes me more sad D;</p>

<p>btw, did we reach an agreement on if it was allantois and chorion or just allantois? thanks</p>

<p>allantois + chorion was what i put. wiki seems to agree.</p>

<p>btw, i’m sorry :(</p>

<p>[chorion</a> definition](<a href=“http://groups.molbiosci.northwestern.edu/holmgren/Glossary/Definitions/Def-C/chorion.html]chorion”>chorion definition)</p>

<p>All right, updated consolidated answers:</p>

<ol>
<li>Diffusion: CO2 > Glycerol > Sucrose > Chloride ion</li>
<li>Western blot assay modification: Isoelectric point</li>
<li>What is not produced by the anterior pituitary? ADH</li>
<li>Lipid monolayer of archaea diagram: The choice with two hydrophilic ends (amphiphilic)</li>
<li>The ethology question about the army: Kin selection</li>
<li>Question about habituation?</li>
<li>Turner syndrome: X0</li>
<li>There was a question about radial cleavage. The answer was echinoderm (or something similar to that).</li>
<li>Island biogeography (greatest equilibrium population) Answer: Least distance, greatest size.</li>
<li>The photomicrograph of the numerous cells: Red Blood Cells of frogs</li>
<li>Stomata open because… Answer: Active uptake of potassium ions</li>
<li>Concentration of pyrimidine: 50%</li>
<li>What is not an example of a secondary sex characteristic? Answer: Reproductive organs</li>
<li>How does ADH work? Increases the expression of aquaporin channels</li>
<li>Ascending loop of Henle is thicker because: Na-K-Cl cotransporter</li>
<li>Qustion about what is not true regarding genetic drift?</li>
<li>Recombination question: 600:200:200:600</li>
<li>Protein deficiency (canned pasta): Sulfur.</li>
<li>Sexual selection question?</li>
<li>Heart: Left ventricle</li>
<li>Question about the primary energy source of some sort of embryo, I think the answer was yolk sac but idk.</li>
<li>Question about what amino acid would be least usable in allowing a gecko to climb up a wall (with diagrams of various amino acids as the answer choices). Answer: Phenylalanine</li>
<li>Vitamin deficiency (necklace lesions): B3.</li>
<li>Colchicine: Dihaploid fertile</li>
<li>Nyctinasty</li>
<li>Fick’s Law: Gills vs. Alveoli: Path length or gradient?</li>
<li>Multiple sclerosis treatment: Closing potassium channels increases duration of action potential.</li>
<li>What period did animals arise that resemble the body forms seen today? Answer: Cambrian</li>
<li>In response to stress, fungi produce zygosporangium.</li>
<li>Not true about Allopatric Speciation: Less common than sympatric speciation</li>
<li>Not true about Allopatric Speciation: Results from sexual selection (I thought #30 and #31 were one question, but my memory could be deceiving me).</li>
<li>Jumping bird: Females responded to the good jumpers because that trait was correlated with good genes</li>
<li>Question about which hormone is produced in abnormal quantities: PTH</li>
<li>If liver was damaged, what would not happen: Production of erythropoietin changes</li>
<li>Klinefelter’s: Nondisjunction during meiosis 2</li>
<li>A question about a virus?</li>
<li>Which order of birds would not feature strong flight muscles? Sphenisciformes</li>
<li>Extraembryonic membranes used for respiration: Both allantois and chorion</li>
<li>Which of the following is not an advantage used to attract pollinators: Sepals.</li>
<li>Which of the following lacks a closed circulatory system: Insecta</li>
<li>There was a question with answer choices including the words: megaphylls & microphylls.</li>
<li>Question about hormones: Adrenal gland</li>
<li>Cation exchange</li>
<li>O-chem lab question (table of info). Answer was the only choice which started with Arginine.</li>
<li>For the carnivorous plants, the one that was false is that it traps insects for energy.</li>
</ol>

<p>Please point out any mistakes I may have made.</p>

<ol>
<li>Question about hormones: Adrenal gland</li>
</ol>

<p>do you remember the other choices?</p>

<ol>
<li>The photomicrograph of the numerous cells: Red Blood Cells of frogs</li>
</ol>

<p>I believe the choice was frog eggs? Sorry if im wrong lol</p>

<ol>
<li>Heart: Left ventricle</li>
</ol>

<p>Can anyone please explain this one?</p>

<ol>
<li>i believe yolk sac is correct</li>
</ol>

<ol>
<li><p>megaphylls was the correct answer i think</p></li>
<li><p>do you remember the other choices?</p></li>
</ol>

<p>Potassium channel blockers prevent leak in MS patients. I’m 100% sure bout this one</p>

<p>you choose chamber that pumps to the entire body -> left ventricle is the logical choice here</p>

<p>the phospholipid and apoptosis question was phosphatidylserine :D</p>

<p>I don’t remember the other choices about the adrenal glands. The choice I picked contained the word: thyroxin, but that’s all I know. As for the megaphyll/microphyll question, at least 3 of the answer choices contained both those words lol. I do not remember what the question was asking for though… I think it dealt with the evolutionary relationship of two groups of plants. As for frog eggs vs. frog blood cells, was the image taken under a microscope? If it was under a microscope, then it would be the red blood cells of frogs. If there was no microscope, then it would be frog eggs. Also, in a frog blood smear, there are spaces between the blood cells whereas frog eggs are more clustered together.</p>

<p>Anyhow, I (or someone else) will update the list later. For now…</p>

<ol>
<li>The image of the numerous cells: Red Blood Cells of frogs or Frog eggs.</li>
<li>Multiple sclerosis treatment: Potassium channel blockers prevent leak.</li>
<li>Fixed action pattern (forgot to add this one in lol)</li>
<li>Phospholipid and apoptosis question was phosphatidylserine</li>
</ol>

<p>Wth, frogs’s blood cells have nuclei. I hate this. ._. That’s so random.</p>

<p>I guess the answer lies with how magnified the microscope was?</p>

<p>I think for no.2, the one about separating the 500kdalton proteins, I put using a lower concentration polyacrylamide gel, since for larger molecular weights, a less dense gel produces more band separation (if I remember correctly from my summer internship; I didn’t do Western blotting but I saw postdocs troubleshooting their experiments, and one thing they did was changing the concentration of the gel)</p>

<p>Dam, I think you’re right. Another one wrong for me ._. . ■■■</p>

<p>One Q was about monocots vs dicots</p>

<p>I put aleurone. I think its right.</p>

<p>I just checked the amino acids in gecko septae question. I think they asked for LEAST likely, so the only polar amino acid was serine :x woops I put the one w/ benzene ring, but that’s nonpolar. ■■■. I think I got a 23 by low, conservative estimates, 28 by high estimate :confused:
no penalty for wrong answers right?</p>