<p>^that was not a choice</p>
<ol>
<li>The question about the zebrafish was what it would be eating at 5 days after fertilization. It hatches from 48-72 hours, so it would definitely be hatched by this time. (That’s one of the reasons it’s used as a model animal.) One source I found online says that Paramecium should be fed to zebrafish that are 5 days to 14 days old.</li>
<li>Path length and surface area seemed wrong to me because both gills and lung alveoli are very thin and have a very large surface area; those are two of the characteristics of respiratory organs. Does anybody remember the other choices, besides gradient?</li>
<li>birds vs. mammals: If this was the question about breathing, then the answer was something with birds breathing unidirectionally and therefore being more efficient than mammals.</li>
<li>There was an answer about deep roots. Don’t grasses usually have shallow roots?</li>
</ol>
<p>grassland grasses are the exception, believe</p>
<p>Now since we have most of the answers, what do you guys estimate the curve at?</p>
<p>Me before the test: I am definitely going to make it to semis.
Me during the test: Wow, this test is insanely difficult.
Me after the test: Hmm, looking back, the questions weren’t too bad.
Me after discussion on this site: OK, nvm, this test was hard lol.</p>
<p>As for the curve estimation. Well, it was definitely a lot harder than the 2011 exam (I’m sure most people agree).
My original estimate was 25. Now, I think it’s going to be 21 (like 2010). But I don’t think I can give an accurate estimate because difficulty is subjective (to an extent) and the cutoff depends on how well people do. I’m certain that the average score will be below 20.</p>
<p>What Filament said, I think cutoff will be in between 2011 and 2010’s cutoff, about 25.</p>
<p>I think I got mid 20’s… damit. I was 1 away from semi’s last year. I’m going to be so annoyed if I don’t make it. ._.</p>
<p>RE: gills vs lungs
Does the fact that a whale shark’s gills are huge compared to a gerbil’s lungs mean gills are adapted for surface area? Does the fact that a bear’s lungs are huge compared to a goldfish’s gills mean lungs are adapted for surface area? Try not to get caught up thinking about just one example.
Consider the medium oxygen is dissolving from/to.</p>
<p>Hi all,</p>
<p>I have put together the questions and comments from this thread in a “usable” format, that may create more questions/discussion or not :-).</p>
<p>I hope that this helps as I have spent a bunch of time on this :-).</p>
<p>There are a few leftover comments at the end that I wasn’t sure which question they corresponded to (I’m a mom, didn’t take the test :-)).</p>
<p>Please forgive the formatting and the numbering, as toward the end, there appeared to be more than 50 questions, but they probably related to other questions.</p>
<p>Will send a bit at a time… I don’t know what my limit is for each post.</p>
<ol>
<li><p>The first question about diffusion: CO2 > Glycerol > Sucrose > Chloride ion
Diffusion: CO2 > Glycerol > Sucrose > Chloride ion
surely it Chlorine defuses easier than sucrose
For the phospholipid bilayer membrane diffusion one, it was chloride ion, not chlorine. In any case, I don’t remember “CO2 > glycerol > chloride ion > sucrose” being a choice. Please correct me if I’m mistaken</p></li>
<li><p>Western blot assay modification: I put the one about electricity but I think the answer is the one about denaturing the proteins.</p></li>
<li><p>What were the other choices for the western blot: isoelectric point, denaturing the proteins. I think I picked the choice with the isoelectric point.</p></li>
<li><p>I don’t remember the other choices. I put the isoelectric point, but protein denaturation seems more plausible. I’m not too familiar with molecular biology laboratory procedures though…</p></li>
<li><p>Answer is the one about isoelectric point
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></li>
</ol>
<p>For the western blot, sure you could make an argument that by adjusting the gel composition (and then running like a 10 meter long gel) maybe you could get proper separation. You could. But you shouldn’t. </p>
<p>In general, if a question has an ‘obvious’ answer, but also another answer that you could argue, through a silly convoluted path, technically fulfils what’s being asked, don’t do it. You’ll be marked wrong, and any sense of superiority you have for having ‘beaten’ or ‘tricked’ the test will be worth nothing. Unless something is explicitly, factually wrong and you have time and opportunity to raise the issue, don’t try to be smarter than the test. </p>
<ol>
<li><p>Western blot assay modification: Isoelectric point
For the western blot, the composition answer may be right, now that I think about it. It depends on whether the proteins have thee exact same mol weight. If that is the case, it is still isoelectric focusing</p></li>
<li><p>What is not produced by the anterior pituitary? ADH</p></li>
<li><p>What is not produced by the anterior pituitary? ADH</p></li>
<li><p>Lipid monolayer of archaea diagram: I believe it was choice A (look up the diagram on wikipedia)
the lipid layer one was definitely not A. It was asking for MONOLAYER → you need an amphiphilic molecule. A would’ve given a normal bilayer, thought it is found in archaea</p></li>
<li><p>Only one of the choices had hydrophilic groups on both ends of the molecule; the answer was that one.</p></li>
<li><p>Lipid monolayer of archaea diagram: The choice with two hydrophilic ends (amphiphilic)</p></li>
<li><p>The ethology question about the army: Kin selection</p></li>
<li><p>The ethology question about the army: Kin selection</p></li>
<li><p>There was a question about habituation, but I forgot the answer choices. I’m pretty sure I got it right though.</p></li>
<li><p>Turner syndrome: X0</p></li>
<li><p>There was a question about radial cleavage. The answer was echinoderm (or something similar to that).</p></li>
<li><p>Island biogeography (greatest equilibrium population) Answer: The island with the greatest distance from the mainland and with the largest size.</p></li>
<li><p>Wasn’t the island biogeography one: largest and closes to the main island?</p></li>
<li><p>I put farther from the mainland, because being closer to the mainland would increase gene flow</p></li>
<li><p>Least distance, greatest size</p></li>
<li><p>Island biogeography (greatest equilibrium population) Answer: Least distance, greatest size.</p></li>
<li><p>The photomicrograph of the numerous cells: Red Blood Cells of frogs (look it up on google images–the other choices didn’t make much sense anyway e.g. the cells were definitely not sperm cells or human erythrocytes)
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></li>
<li><p>The photomicrograph of the numerous cells: Red Blood Cells of frogs</p></li>
</ol>
<ol>
<li><p>Stomata open because… Answer: Active uptake of potassium ions</p></li>
<li><p>There was a question asking about the concentration of pyrimidine; I believe the answer was 50%</p></li>
<li><p>What is not an example of a secondary sex characteristic? Answer: Reproductive organs</p></li>
<li><p>What were some other choices for the secondary sexual characteristics question?</p></li>
<li><p>How does ADH work? Increases the expression of aquaporin channels</p></li>
<li><p>Ascending loop of Henle is thicker because: Na-K-Cl cotransporter</p></li>
<li><p>For the why the ascending loop is thicker, was there a choice saying its thicker because of more water channels/aquaporins? I’m asking this because I’m not sure if I picked the Na-K-Cl cotransporter.</p></li>
<li><p>The descending loop is permeable to water, not the ascending loop. Ions (Na, K, Cl) are reabsorbed via the ascending loop.</p></li>
<li><p>There was a question about what is not true regarding genetic drift? I think the answer was something along the lines that it stops variation or something.</p></li>
<li><p>There was a recombination question, and I think the answer was 600:200:200:600</p></li>
<li><p>What element should you first test for when there is a protein deficiency? I put sulfur. Another answer choice was iron.
protein deficiency should be sulfur…
lack of protein → lack of sulfur (CHONS)</p></li>
<li><p>Protein deficiency (canned pasta): Sulfur</p></li>
<li><p>There was a question about sexual selection–I don’t remember it though.</p></li>
<li><p>I picked E, something about sexual selection poses risk to both male or female? Might have been wrong since they asked for what was false</p></li>
<li><p>There was a question about the heart–I think the answer was right atrium.</p></li>
<li><p>It was about injecting some sort of paralyzing/fixing chemical into which part of the heart.</p></li>
<li><p>Yes, that was it. I forgot the name of the chemical though
question on the heart was left ventricle (whole animal fixing)</p></li>
<li><p>Heart: Left ventricle
you choose chamber that pumps to the entire body → left ventricle is the logical choice here</p></li>
</ol>
<ol>
<li>There was a question about the primary energy source of some sort of embryo, I think the answer was yolk sac but idk.</li>
<li>i believe yolk sac is correct</li>
<li><p>The question about the zebrafish was what it would be eating at 5 days after fertilization. It hatches from 48-72 hours, so it would definitely be hatched by this time. (That’s one of the reasons it’s used as a model animal.) One source I found online says that Paramecium should be fed to zebrafish that are 5 days to 14 days old.
For the zebrafish larvae, I put Paramecium because that’s the main food source of zebrafish larvae, but it might have been yolk sac. I don’t remember what age the zebrafish larvae were supposed to be.
zebrafish was 5 days after fertilization → google source said “to not feed them because yolk is sufficient”.</p></li>
<li><p>Could this have been the question about which extraembryonic membranes are used for respiration? The answers were something like: (A) yolk sac (B) allantois (C) chorion (D) both A and B (E) both B and C. The answer was E.
btw, did we reach an agreement on if it was allantois and chorion or just allantois? thanks
**
allantois + chorion was what i put. wiki seems to agree</p></li>
<li><p>There was a 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). I put phenylalanine but I’m pretty sure that is wrong. I think we have to think in terms of Van der Waals forces or something.</p></li>
<li><p>gecko feet/Van der Waals forces: Van der Waals forces would make it a nonpolar amino acid.</p></li>
<li><p>Phenylalanine
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.</p></li>
<li><p>There was a question about vitamin deficiency. I guessed vitamin E–but I doubt that is correct.
B3
btw, what was the vitamin deficiency question? the one that mentioned necklace lesions? Was it B3? (that’s what i guessed blindly)
**
yes it was b3 </p></li>
<li><p>Vitamin deficiency (necklace lesions): B3</p></li>
<li><p>There was a question about pollen with answer choices like: dihaploid fertile, haploid sterile, etc.
the question about Colchicine is dihaploid fertile. its used to artificially produce polyploidy in crop plants. its a spindle inhibitor</p></li>
<li><p>Colchicine: Dihaploid fertile</p></li>
<li><p>There was a question about how plants respond to light/darkness or something. The answer choices were Thigmonasty, Seismonasty, epinasty, nyctinasty. I put epinasty but I’m pretty sure the answer is nyctinasty.</p></li>
<li><p>Nyctinasty</p></li>
<li><p>There was a question about Fick’s Law: Gills vs. Alveoli.</p></li>
<li><p>Was the answer to the Fick’s law: larger surface area or something in fish?</p></li>
<li><p>I put that there was a larger gradient, thinking of countercurrent exchange in gills. Both gills and lungs have a large surface area</p></li>
<li><p>Man, screw this question. This was my logic: it wouldn’t be gradient for sure, because gills extract oxygen from the water, which is way less concentrated in oxygen than air (which is what lungs extract oxygen from). As mentioned, both lungs and gills are rather expansive. I think there was a temperature choice? - temperature in lungs would usually be higher than temperature in gills. As for path lengths, water has to pass over the entire length of the gill, while in a lung the air only passes through a few millimeters of alveolus. So path length is the correct answer imo.
the fick’s law was maximize the gradient: you don’t have countercurrent exchange in mammalian lungs, while you do in gills
I see what you’re saying, but my logic is: no matter how hard you countercurrent-exchange, gills are going to move oxygen from water to blood, while lungs are moving oxygen from air to blood. Air is hundreds of times more oxygen-concentrated than water, so ultimately the oxygen gradient in a lung is going to be enormous compared to the gradient in a gill.</p></li>
</ol>
<p>Granted, I still see your point. Out of curiosity, supposing you were correct, how would you justify that the answer is not path length?
26. Fick’s Law: Gills vs. Alveoli: Path length or gradient?
26. Path length and surface area seemed wrong to me because both gills and lung alveoli are very thin and have a very large surface area; those are two of the characteristics of respiratory organs. Does anybody remember the other choices, besides gradient?
RE: gills vs lungs
Does the fact that a whale shark’s gills are huge compared to a gerbil’s lungs mean gills are adapted for surface area? Does the fact that a bear’s lungs are huge compared to a goldfish’s gills mean lungs are adapted for surface area? Try not to get caught up thinking about just one example.
Consider the medium oxygen is dissolving from/to. </p>
<ol>
<li>There was a question about Multiple sclerosis treatment. The answer was closing potassium channels increase duration of action potential.
Potassium channel blockers prevent leak in MS patients. I’m 100% sure bout this one </li>
<li>Multiple sclerosis treatment: Potassium channel blockers prevent leak</li>
<li><p>Multiple sclerosis treatment: Closing potassium channels increases duration of action potential.</p></li>
<li><p>There was a question about during what period did animals arise that resemble the body forms seen today. I put Cambrian because of the Cambrian explosion.</p></li>
<li><p>In response to stress, fungus produces: zygosporangium?</p></li>
<li><p>Yeah, something like that. The other choices were something like: The fungi would begin to engage in mycorrhizae or something, which is wrong. The fungi was black bread mold (a zygomycete).</p></li>
<li><p>In response to stress, fungi produce zygosporangium</p></li>
<li><p>Allopatric Speciation: less common than sympatric speciation or vice versa (since it may have asked for which is not true)</p></li>
<li><p>Not true about Allopatric Speciation: Less common than sympatric speciation
30-31. For some reason, I think that those were in the same question. It asked which was not true about allopatric speciation, and I thought one of the choices was allopatric speciation is less common than sympatric speciation, and another choice was allopatric speciation results sexual selection. Maybe it’s just me</p></li>
</ol>
<ol>
<li>Allopatric Speciation: does not result from sexual selection</li>
<li><p>Not true about Allopatric Speciation: Results from sexual selection (I thought #30 and #31 were one question, but my memory could be deceiving me).</p></li>
<li><p>Jumping Bird: Was it A or C? There was a small difference in that A talked about showing off physical characteristics while C mentioned the word “courtship” and mentioned that the female could observe the male genes.</p></li>
<li><p>There was one option that mentioned that the females responded to the good jumpers because that trait was correlated with good genes. It may have been A.
A mentioned good physical abilities; C mentioned the word “courtship” and mentioned showing off good genes (didn’t mention physical abilities)</p></li>
<li><p>Jumping bird: Females responded to the good jumpers because that trait was correlated with good genes
A mentioned good physical abilities; C mentioned the word “courtship” and mentioned showing off good genes (didn’t mention physical abilities)</p></li>
<li><p>PTH</p></li>
<li><p>Yeah, I remember PTH. Was PTH a question or an answer?
PTH was an answer to the one regarding which hormone is produced in abnormal quantities. the neural/cardiac problems gave away the problem as being one of ion quantities and PTH regulates calcium levels</p></li>
<li><p>Question about which hormone is produced in abnormal quantities: PTH</p></li>
<li><p>If liver was damaged, what would NOT happen: production of erythropoietin changed or something.</p></li>
<li><p>If liver was damaged, what would not happen: Production of erythropoietin changes</p></li>
<li><p>Klinefelter’s: something in Meiosis 2 of the mother.</p></li>
<li><p>Yes, that was the answer. I got it wrong though, since I forgot what Klinefelter’s syndrome was.</p></li>
<li><p>This question is pretty interesting. I had a good long debate with this over my friend (also a Finalist last year). We’re both pretty sure the answer is nondisjunction of the mom during meiosis I. Can anyone remind me what the question is? Normal father, carrier mother, child is XxY, am I right?
according to wikipedia: The extra X chromosome is retained because of a nondisjunction event during meiosis I for klinefelter’s </p></li>
</ol>
<p>i thought it was nondisjunction in meiosis II, because that would guarantee you had two alleles of one type XXY. i have a couple of friends who agree with me </p>
<p>Unfortunately, I can’t remember the details to this question, but when I work it out now, the answer does seem to be meiosis II. It could be that both me and that friend borked in figuring it out at the time. Are you certain the child’s genotype was homozygous for whatever condition?</p>
<p>I’m pretty certain of my answer. If the child is to have the condition, it would have to have all recessive alleles (extrapolating from the info given in the text of the question). </p>
<ol>
<li><p>Klinefelter’s: Nondisjunction during meiosis 2</p></li>
<li><p>Virus named Ijustmadethisup (don’t remember the question, unless it’s already mentioned?)</p></li>
<li><p>Which order of birds would not feature strong flight muscles? I put Piciformes because they sounded small, but I think the answer was Galliformes (turkeys, chickens, quail, etc.) because they don’t fly very much.
The question about the bird classification was Struthioniformes. Those are flightless birds (kiwis, ostriches, cassowaries) and thus have no keel and no flight muscle anchorage. I am rather sure I got that one correct btw.
**
Sphenisciformes is the answer to that one, penguins,atually </p></li>
<li><p>This is definitely Struthioniformes</p></li>
<li><p>sure? my teachers says otherwise. and wikipedia agrees its sphenisciformes
And Struthioniformes just jumped out at me when I saw the question. I don’t know much about penguins and so I really can’t say.</p></li>
<li><p>Which order of birds would not feature strong flight muscles? Sphenisciformes</p></li>
<li><p>regarding extraembryonic membranes used for respiration, I agree that it was both allantois and chorion.
However, regarding extraembryonic membranes used for respiration, I agree that it was both allantois and chorion.
I thought it was only allantois, are you sure?</p></li>
<li><p>Extraembryonic membranes used for respiration: Both allantois and chorion</p></li>
<li><p>There was a question like which of the following is not an advantage used to attract pollinators. The choices were sepals, petals, a foul odor, patterns visible only under UV light (or something). I put the UV floral patterns option, but I don’t think that’s right…</p></li>
<li><p>There was a question like which of the following is not an advantage used to attract pollinators. The choices were sepals, petals, a foul odor, patterns visible only under UV light (or something). I put the UV floral patterns option, but I don’t think that’s right…</p></li>
</ol>
<p>I believe the answer was sepals. Some insects see infrared
39. Which of the following is not an advantage used to attract pollinators: Sepals</p>
<ol>
<li>There was a question about which of the following lacks a closed circulatory system. The answer was: Insecta.</li>
</ol>
<ol>
<li>There was a question with answer choices like: megaphylls, microphylls, etc. I don’t remember that question but I do remember getting angry at myself after the test for mixing up megaphyll and microphylls haha.
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.</li>
<li><p>There was a question with answer choices including the words: megaphylls & microphylls</p></li>
<li><p>There was a question like which hormone is not paired with its function. I think I put thyroxin, but I don’t remember it that well.</p></li>
<li><p>I remember the correct answer for this one having something to do with the adrenal glands</p></li>
<li><p>Question about hormones: Adrenal gland</p></li>
</ol>
<p>do you remember the other choices?</p>
<p>don’t remember the other choices about the adrenal glands. The choice I picked contained the word: thyroxin, but that’s all I know.
42. Question about hormones: Adrenal gland</p>
<ol>
<li>There was another question about the term that describes cations going from soil to roots. I put cation cotransport, but the answer should have been cation exchange.</li>
<li>There was another question about the term that describes cations going from soil to roots. I put cation cotransport, but the answer should have been cation exchange.</li>
</ol>
<p>I put cation cotransport. Why do you say that it should be cation exchange?
There was another question about the term that describes cations going from soil to roots. </p>
<p>cation cotransport or cation exchange??
**
Cation exchange. I think it’s a rigorous term; you can’t call it anything else</p>
<ol>
<li><p>Cation exchange</p></li>
<li><p>O-chem lab question (table of info). Answer was the only choice which started with Arginine.
the ochem question was what it was b/c sudan’s solution stains triglycerides and ninhydrin reacts with free amine groups (and thus reacts like crazy with amino acids, esp. basic amino acids). that was the only choice that fit.</p></li>
<li><p>For the carnivorous plants, the one that was false is that it traps insects for energy.
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></li>
</ol>
<p>44.? There was a question asking what would happen to an egg or something if a substance that I never heard of was added do it.</p>
<p>Choice A was something like “it would grow but produce no offspring”
46. Fixed action pattern (forgot to add this one in lol)</p>
<ol>
<li>Phospholipid and apoptosis question was phosphatidylserine
the phospholipid and apoptosis question was phosphatidylserine<br></li>
</ol>
<p>48.? One Q was about monocots vs dicots</p>
<p>I put aleurone. I think its right</p>
<p>I think the answer to the monocot vs dicot one depends on whether they were talking about what do monocots have that dicots don’t. For some reSon, I remember the problem stAtement being the reverse</p>
<p>For the aleurone question, it asked which was false. The answer choices named various structures stating whether both dicots and monocots had it or only one had it.</p>
<p>anyone know the aluerone one? i think another choice was “seeds of mono/dicots have pericarp”. and the other choices involving coleorhiza/coleoptile/radicle were all true I believe.
**
dicots dont have coleoptiles do they?
**
im pretty sure the dicots vs monocots one was the aleurone layer </p>
<p>For the aleurone question, it asked which was false. The answer choices named various structures stating whether both dicots and monocots had it or only one had it.</p>
<p>49? does anyone remember the dates for the geologic time period question? I think I put carboniferous, devonion, or permian because I remember it was like 400 or 300 mya </p>
<ol>
<li><p>Amino acid that transported water: Asparagine</p></li>
<li><p>A question about birds vs. mammals
The birds vs. mammals was the one about breathing, I think</p></li>
<li><p>birds vs. mammals: If this was the question about breathing, then the answer was something with birds breathing unidirectionally and therefore being more efficient than mammals.</p></li>
<li><p>A question that asked which of the following is NOT a plant adaptation in the grassland.
Regarding adaptations in the grassland: not true is that trees store wT mostly in the roots and their trunks have little Suberin</p></li>
<li><p>There was an answer about deep roots. Don’t grasses usually have shallow roots?
**
grassland grasses are the exception, believe</p></li>
</ol>
<p>random stuff, please let me know what questions these correspond to (by number)</p>
<p>The virus one: the virus was causing an overabundance of hormone. The answer was definitely PTH.</p>
<p>The first amino acid question was serine, the second was the only polar one (I don’t remember the choices or my answer).</p>
<p>The answer to which hormone does not match function was mineralocorticoids for sure</p>
<p>^#33, #22, #42 respectively.</p>
<p>Anyhow, most people agree that this exam was easier than the 2011 one. (The 2011 gave a lot of freebies: lysosomes have lowest pH, definition of succession, what comprises a community, etc.). What about in comparison to the 2010 exam (cutoff: 21)? Comparing this with the 2010 one, I personally thought this one was a lot harder. But, of course, others may disagree and even so, it doesn’t necessarily mean that the cutoff will be lower.</p>
<p>I don’t think the cutoff will be below 21, nor do I think that the cutoff will be higher than 27. I think that there’s a better chance that the cutoff will be in the low 20s rather than high 20s. But that’s just me. Looking at previous years threads, the cutoff predictions were pretty inaccurate.</p>
<p>“The virus one: the virus was causing an overabundance of hormone. The answer was definitely PTH.”</p>
<p>I would really appreciate it if anyone could write the full problem or the answers choices or both. Thanks :]</p>
<p>S said that regarding the heart question tht it is the right atrium because the wording of the question said something about which area you would inject the poison to kill the heart (not the rest of the body). The left ventrical would kill the rest of the body before making it back into the heart, whereas if you inject it in the right atrium, it would reach all chambers before entering the body and would kill the heart.</p>
<p>He’s not here right at the moment for clarification, but there’s what I got :-)</p>
<p>^I was really confused about this question. Didn’t the question state that the organism was already dead?</p>
<p>S said the premise behind the question was something about donating organs. You can’t donate organs unless the heart is already dead (dies first?) or the person is living. </p>
<p>So you would not want the poison in the body, just in the heart.</p>